On the subject of IAx brakes... A few key considerations from my experience:
1) The IA 16 brakes are really bad. To anyone who gets an IA 16, I highly recommend a brake swap. They feel spongy because I think they are made of cheap stamped pot iron. You can make a vast improvement with just a move to Ultegra brakes for under $100 total. Or, next level up could be the Vision Trimax like from the rest of the IAx line. I went with the Tririg for all of its marketing claims: aero, adjustability, cosmetics, mechanical leverage, etc.
2) The rear brake cable routing is not good with the Bayonet 3 bars. The cable passes into the stem and under a cosmetic plate and then takes a hard turn into the frame. If the plate is tightened too much, it will crush the brake cable. The factory assembles this, not the LBS, and mine was crushed. I replaced my rear brake cable and vastly improved brake feel. I have the plate much looser now, until I get a future cockpit upgrade with better cable management.
3) The rear brake has an in-line barrel adjuster between the bars and the stem. The space is tight, and the cable needs to curve between the bar outlet and the stem inlet. The result is that the barrel adjuster causes additional friction in the rear brake line. I left that in when I replaced the cables, but I will be getting rid of that shortly with another cable replacement.
4) The Felt brake levers are pretty good. In my quest for improved braking, I also upgraded to the Shimano BL-TT78 brake levers. They are nice, but I do not think that they materially improve braking strength over the Felt levers.
I forgot the IA16 doesn't come with the Trimax brake (mine's an IA14) so when I spoke about the stock brake, I meant the Trimax!
I'm surprised to hear you say the factory install the rear brake cable because mine is routed very badly. I think perhaps the vendor re-routed it as I'd requested right hand front braking. The rear brake cable passes through the stem from left to right but is not routed through the length of the stem. It enters the frame vertically in front of the Calpac and squeeks badly when the handlebar is turned. It's rubbing badly and has abraded the plastic outer layer entirely off part of the cable sleeve leaving only the inner metal coil. I intend to re-route it myself as soon as I get time in the next week or so. Anyone got good advice on how best to do this? I haven't investigated yet but I presume the cable is fully sleeved within the frame and it'll be straightforward to pull out the existing inner, correct the problem section of the outer and slide in a new inner cable? Is that correct?