305 v. 405

I'm starting to really feel 'at one' with my 405. That's largely because I have now collected all of the add-ons for it--heart rate monitor, foot pod, speed/cadence sensor, and the bike mount. I also learned how to effectively use the TrainingCenter application. It's not perfect, but it gives you a lot of ways to plan your workouts. 

Unlike the 305, the 405 is actually watch-sized. You can wear it out and people won't think you're a weirdo. My dad seriously wears bigger watches than that, and they don't have GPS built in. I'll break down what I understand are some points of comparison below:

 Battery life: Hasn't been an issue for me since my longest training days aren't more than a c ouple of hours long. As a test, I started the timer with the watch on my desk (GPS on and receiving) until the battery ran out, and that took about 8.5 hours. Remarkably, the distance registered as almost a mile. Also worth noting is that charging the unit doesn't disrupt the recording functions, though it does lock up the interface.

Compatibility: The 405 still isn't mac compatible (shouldn't be more than a few weeks away at this point). That sucks for me, as I'm a mac user, but it works pretty gracefully in Parallels/VMWare. The wireless connection is pretty cool, though.

 GPS performance: I don't know about the 305, but the 405 fixes on satellites in <10 seconds. Often it's more like 2-3 seconds. I've heard that the 305 takes much longer.

Display: I sometimes wish it were easier to track more stats at a time, but I'm starting to adapt. The 405 displays 1-3 fields per 'screen,' and you can configure up to around 4 screens that you cycle between (automatically or manually). I typically run 2 screens on auto-cycle because I find more than that to be cumbersome.

Bezel control: The touch bezel works pretty well, but it takes some getting used to. I've heard complaints about people not being able to use it when they're really sweaty or it's raining, but so far I've found it pretty responsive. I also adjusted the sensitivity of the bezel in the settings and found that to be helpful.

I have a couple of friends who swear by their 305's - and I love my 405 just as much.  It will take some getting used to if you've had the 305 for a while, but it's a nice device.  The 305 does have a multisport mode, the 405 does not. 

Garmin is way overdue for a truly waterproof Triathlon device.  I wonder if I could beta test it for them? 

Does the 405 allow HR, time, dist, pace on the same screen?

Does the 405 have a feature to auto lap every mile?

I am also trying to make the decision.  If the 405 gives me the data I need I can't see buying the 305...it's just too big for 2008.  Reminds me of the watches I had as a kid where you wind up a car and it shoots off your wrist.

Not all 4 at once.  You could set it to read 3 of those data fields per screen and you get three screens to modify plus an extra screen for HR if you have the belt.

Yes - you can automatically mark a specific lap or distance.