Some roadies will sneer at you fitting clipon tribars but who cares?. You do what you want to do and no one should need to confirm to some "unwritten code of conduct" when it comes to fitting crud to your bike.
I have a set of TranzX clipon tribars on my FP1. I'm undecided as to whether I will keep them on there but so far I have to say that they are actually not bad. When down on them the position isn't too extreme and quite comfy for long straights and downhill sections. Just don't try using them when there is a lot of traffic around ( in case you need to brake or change position quickly ) and watch out for the road surface ahead with even more of an eagle eye than normal when you are on the tribars. Hitting a big chucky or pothole when in that position isn't conducive to you staying on the bike as I found out to my cost earlier this year.
The main advantage I find they afford is another hand position. Was out today for a quick 26 mile blast and I find that being able to change position to something completely different from hoods/drops etc allows for much more comfort. That's about the main advantage of them as far as I'm concerned. They do appear to allow you to increase average speed over a set distance even on a road bike at novice level but as i said you really, really have to take some time to get used to them and watch the oncoming road surface very carefully indeed. Disadvantage is that the basic clip on alloy ones do add a bit of extra weight up front which you may or may not notice depending on how much of a weight weenie you are.
Give 'em a go if you fancy it, you will either love 'em or hate 'em. I grabbed a set on
eBay for under £20 inc postage. I figured if I didn't like them then it wasn't a great loss to write off. Tip when fitting them - cut some old inner tube to the width of the mounting clamps and mount the clamps on the inner tube. This will save any marks on your bars when it comes to tightening them up.
Incidentally, in this months Triathlon Plus mag there's a big product test of tribars both clip ons and rather expensive integrated ones.
A couple of pics from this afternoon :-