Are they pushing you toward a tri-bike? A tri-bike will put you in a more aerodynamic position which will be faster (as long as you train enough on it to adapt to that position). The forward "tri" position may also leave you fresher for the run but I don't think that's a huge difference. For ~10 years, I used an standard road bike with clip-on aeros (which did not put me in a "forward" position) for triathlons and I do recall that getting off the bike and transitioning to the run was a little tougher - maybe lose ~10 seconds in the first 1/2 mile or so while your legs get used to running. But I'd wait a few years before plunking down a lot of money on a specialty tri-bike unless you already are planning to race a lot of triathlons in the coming years.