I am sure a good carbon frame will give more than 17 years!
Recently I had the chance to compare my 1990 Harry Hall in Columbus SLX with a modern carbon bike, a Specialized Roubaix Comp, which is designed exactly with the older rider in mind. I loved the HH and wasn't really bothered about the Spesh so I think I can say I approached the test with a genuinely open mind. The difference was clear from the moment I set off up the road and the further I have ridden the Spesh the clearer it has become. The HH was a respected frame in the best steel available at the time and by any standards it was a great bike. The fault lies more with the 1990 geometry really but by comparison with the modern carbon frame the HH was brutish, choppy, too short and thoroughly uncompromising. The carbon frame by contrast is light, smooth riding and goes like a rocket as well as feeling as if it was tailor-made for my shape.
If your budget is limited
Wiggle are offering the Focus Cayo at a very competitive price right now and the reviews are excellent.