Hi

I have a 14.5" SC chameleon which I use for XC. Obviously it's too small for this for me (I'm 5'10). How much difference in terms of performance and ease of riding could I expect to get from a bigger size frame? The chameleon is a fantastic ride – I'm torn between not doing anything and saving cash, buying a bigger chameleon (£500) or going for a completely new FS bike.
Opinions welcome…
Cheers

I get grief from our resident spannie for riding bikes that are too small for me. It just depends on what you prefer.

Depends on your prefered riding. I'm 6' 2" and ride a Commencal Meta 4x (around 15" seatube) and a 19" charge duster. I ride the Meta most of the time, but really struggle on rides over 3hrs.
The correct size frame makes it easier for longer rides and rides where you need to be seated alot, as you can set the most efficient saddle height. Where as smaller frames are (personally) better for more technical/twisty descents and singletrack as you can move the bike around under you more easily.
HTH