swimsuit or trisuit?

Male, female, gender non-specific, get tri shorts and top or a tri suit. They're made to wear the whole race.

Wearing anything under the shorts for biking is asking for chafing. Just something to think about.

Awesome thanks! I didn't think about the bike/chafing issue, being a swimmer first!

If you plan on doing all your swim training in the tri shorts try to be diligent about rinsing them off after each swim, otherwise the chlorine will eat away at them.

I did my first tri in my one piece with bike shorts (didn't have tri shorts yet). This was a reverse tri that started with the run and I had to be really particular about where my tri money was spent. I wore the bike shorts over my suit with a t-shirt for the run and the bike, then since the swim was last I just pulled everything off but the swimsuit. I also did a couple of full regulr mock sprints pulling the bike shorts over my wet one-piece and did the biking and running in that get up. I didn't have any chafing issues or any issues at all. 

I have trishorts now, which I wouldn't have to take off, and I would consider wearing it over my one-piece except the chlorine has rendered it too limp to give me the proper support for the run. Instead, I found a compression shirt at Ross (I dunno...like $5?) that I'll be wearing with a sports bra and the shorts next weekend. For me, it is a money thing. I bought the cheap Avero $29.00 trishorts and I still think $30 is a ridiculous price. There is really nothing special about these garments--just that I guess a lot of triathletes have money to spend, so they know they can get a lot of money for them.

Go pay $60-90 for a pair of Zoot shorts and come back and see if you say there's nothing special or that they're not worth the money.
Oomph shorts are damn good and about 2/3 the price of Zoot. They're what I use to train in for bike.

I've had one pair of shorts I got for about $30. I won't make that mistake again.

I'm not suggesting that the more expensive shorts are not better quality at all. I am only suggesting that is it a lot of money to pay for a pair of shorts, period, I don't care how wonderful they feel or perform.  And on my budget, and this early in my tri experience, spending that much on a pair of shorts would cause me to hyperventilate...in fact, I'm getting a little dizzy right now just thinking of it. Had the same reaction when I walked into my LBS and was told I would not be able to buy a decent bike for under $700.  What can I say? I remember when a decent 10-speed was under $100.

But I am curious what the difference in performance is in the different shorts? I wore my Averos for my OWS clinic and a run afterward and yesterday for a 12 mile bike ride and a lake swim afterward. They were actually more comfortable on the bike than my regular, more padded, bike shorts which surprised the heck out of me. I had no issues, but then nothing to compare them too.  Maybe I'm better off not knowing what I'm missing! And I'm only barely doing sprints right now, so maybe for longer distances I'd feel differently.

That's a very valid point. I'm doing HIMs this year. I've got shorts (the cheaper ones) that I'll ride for 1- 1.5 hours in but I won't even consider them when the ride goes about 2 hours. It's like trying to slide on sandpaper and not being able to get off it. I've found that I'm still comfortable in the more expensive ones at 4 and 4.5 hour rides.