I know your considering a faster road bike at the mo, frames usually have a warranty so if it breaks you get a new one.
When i first got my Allez (admittidley a practicle sort of race bike) I was all careful with it, now its the only bike I use, dirt tracks, bridleways and on the road , Im not much under 100kg and the bike is fine.
I have changed the wheels for Askiums , which are also used on cyclocross bikes and the tyres for 25mm Gatorskins. I could be tempting fate here, but the bike feels very solid, could be different if you get some extreme lightweight carbon job.
...ok...well I am I 'little' heavier...at jus tunder 19stone...so I am thinking I should avoid a full carbon frame...however what say you to a aluminium frame with carbon fork? Like the bianchi's...maybe I should ask Bianchi...