Garmin 305 for tempo and intervals?

First, I don't think you need anything special for a tempo run, just a watch.

Second, the distance measurement is accurate enough to do intervals with.  I've done longer intervals (mile) on a marked trail, and the Garmin was close enough.  I don't look at pace, I just see time and distance.  I do know that the current pace number is pretty much worthless, and the lap pace can be deceptive for the first tenth or so.

ETA:

If you have a track or marked course, no need to use the Garmin for more than a stopwatch.

I like mine as well.  It can all be done with a regular watch, but what I like about it is you can set up your workout at home on the computer, then load it on to the watch.

You run the workout, and the garmin will beep when to switch phases (interval, rest period) whether by distance ran, or time ran.  It will also record all the splits for you and the associated info.

So I turn it on, start the workout, listen for the ques, and never look at the watch. 

No, it will beep a LOT.  The problem is, it takes the last couple points it read, figures the distance and the time to cover it, and figures your pace.  So really, it gives you the pace for the previous several hundred feet or so - NOT the current pace.  You may slow down, but the pace won't change for about 5 seconds or so on the garmin.  But if you work on a consistant pace, it will dial in to what you want within a couple seconds.  Just make small changes to pace, wait for 5-10 seconds to see the result, then make more changes.

BUT, I have found that over a half mile, I can keep splits within 5-10 seconds of each other, and not have to make any significant changes to pace in the last 100 yards or so to compensate.

In a word: No.

The GPS struggles to accurately calculate pace at slower speeds (works great on the bike though) at any given time the pace my 305 shows me varies by a minute or more.  I set it to auto lap every mile, and display my pace/lap for a more consistent reading.  I imagine you could do this every .5 or .25 miles and get similar accuracy, you just can't look down at your pace and have an instant idea of what pace your running no matter what you do.

To answer one of your initial questions, Amazon has by far the best price for a new unit that I could find after several weeks of shopping, $190 with the HRM:

http://www.amazon.com/Garmin-Forerunner-Wrist-Mounted-Fitness-Computer/dp/B000CSWCQA/ref=pd_bbs_sr_1?ie=UTF8&s=electronics&qid=1222387727&sr=8-1

You also can try your luck on ebay, with a refurbished unit but I haven't heard anything about whether or not they are worth the "risk" to save a little money

So the Garmin probably won't be fast or accurate enough for 400m intervals, but if I focus on the "average pace", do you think it's good enough for 800m intervals and longer?

As for using it on the bike, is the cadence sensor wireless?  Is it easy to switch from bike to run with the quick release so you can use it on a brick?

I agree with most of the above.  I don't trust it's pacing on the run for distances less than 1/4 mile, so for intervals of that length it is a stopwatch. I don't find this to be a problem -- I don't find myself 'staring at the watch' for intervals that short anyway; I just run them and check at the end how I did, and adjust accordingly.  In fact, for any interval, I don't look at the watch at all while running the interval -- only after. (I never do intervals longer than 1 mile each.)

I find that the Garmin really comes into its own on tempo runs and long runs.  In those situations, I find the feedback that it gives during the run to be very useful.

Yes, the cadence detector on the bike is wireless.  It also calculates speed and distance, even while on the trainer.  The numbers that it shows you in this situation (apart from cadence) probably don't mean much, but it gives your something to look at while you're on the trainer.

Overall, I'm very glad to have it.  I travel a lot and  it makes running in foreign cities much easier because I don't have to measure my routes by other means.

I have no alarms on mine.  You're better off without them, anyway.  So you run 5 seconds too fast over a mile interval.  Big deal.  The Garmin will beep incessantly, and irritate you until your average pace drops to a sufficient point.  You're better off maintaining your pace over that mile than fluctuating anyway.

Use the Garmin to track the distances, elapsed time, and lap pace.  I wouldn't set the alarms.

ok, well I'm diff than the other responders.  I love my 305!!  Don't use it habitually, but for fartleks, intervals, tempo runs. yeah baby, it is the da bomb!  Now if you are just purchasing for speed work, I would consider twice.  If you plan on using it for more than speed training, etc.  yeah, it is worth the purchase. 

N~

First, I love technology, but I cannot imagine doing tempo runs, interval work outs or long runs without it.  I set up the work out before I head out the door and I am good to go.  You cannot get too caught up in whether you are exactly on pace using the lap function for shorter intervals.  I do not use the alert function because the beeping would drive me nuts when I am just a little slower or faster than what is expected.

I have not used it on the bike, but I have friends that do.  I have an Edge for that.

OK, so beeping is out.  I'm still undecided whether to purchase the Garmin 305, primarily because I'm not sure if it'll raise my training to a higher level.  By way of background, I've been running with my timex and basic HRM for over 12yrs.  The results have been quite satisfactory.  I do long runs in Z2, tempo in Z4, intervals in Z5a, nothing fancy.  My 10K PB was set over 10yrs ago, and I'd love to break that next yr, in as much as I'd be 11ys older (I'll be 49 then) since my PB was set.  I'm shooting for 5sec/mi faster over 6mi.  I've looked at some training plans (eg smart coach at Runner's World), and the tempo and intervals training pace are a lot more precise compared to what I've been used to.  For example. 800m @ 3:44, then a few wks later, 800m intervals @ 3:42, then a few wks later, 800m intervals @3:40.  I'm not sure I can run such a precise pace w/o sth like Garmin, not sure if I can run such a precise pace WITH Garmin. 

I suppose my question is really a training question - does training at very precise paces yield better results than the basic training I've been doing (training pace based on type of run - easy vs tempo vs intervals, fitness level, RPE and HR), all other things (such as volume) being the same?  I see many of you don't even worry about the pace on the Garmin during your training runs, let alone keep it to w/in 5sec of the target training pace. 

As an aside, I can see how the Garmin current pace can fluctuate wildly.  Our arm swings back and forth during running and depending on where the arm position is when the signal is picked up, I can see it may even think we're going backwards when the arm is in the down and back position.