Here is what I'll say in regard to the choice of a bike. My first bike I went to my LBS and said, I have $xxxx, can I get a bike. They put me on top of a bike, made a few minor adjustments and out the door I went. I then started learning about positioning, etc. Thankfully that bike worked for me. When I asked my LBS about getting more aggressive, they said usually they don't people in an aggressive position unless the person asks to be.
I guess I'm trying to tell you that bike stores will listen to you but in general they'll set you up in a very comfortable position that works for the most people but maybe isn't optimized.
As I stated, I've become a believer in a steep seat angle. Blue and Kestrel build bikes around slacker seat angles, Jamis and Felt build bikes for steeper seat angles.
Just to give you an idea of the fit differences: my ideal bike has a stack(height of the bike) of about 49-50cm and a reach(length of the bike) of about 39-40cm
Talon 54.8 stack, 39.3 reach
Blue 51.5 stack, 39.5 reach
Felt 50 stack, 40.5 reach
Jamis 49.3 stack, 40.2 reach
So, I guess all I'm trying to say is the Talon with an appropriate reach, would be about 5cm too high for me. Blue, I'd probably need a -25 degree stem, Felt is right on; Jamis maybea small spacer.
Coming from a road bike, the Talon will feel more similar to you. There is a little bit of adaption time going from a road to tri bike, so don't be worried if you don't feel 100% at home on a true steep geometry tri bike right away.