I've swam competitively for 9 years now and i've found that jammers have been best for training in and the best for racing in is a some speedo racing LZR elite 2. These are the best i've found for the price and recently upgraded to these too.
Any more questions?
This piece of gear takes some time to get use to when you switch to jammers, but they are great for triathletes. I use Mosconi Hydraskin myself; I purchased a pair from ProSwimwear which have been a great choice if you are interested.
I don't see why they wouldn't be good, if they are comfortable, go for it. I've heard of many people wearing skins for swimming, so its really personal preference.