I shouldn't worry about braking performance Dom, unless you're pushing it into some heavy corners at high speeds you'll not notice much difference. You have to keep more of a look out for potholes and bumps in the road and manhole covers which can be slippery. You'll notice the difference in how fast you can go. Not so much like driving a tractor.

Heres some more good sites.

http://www.bikepimp.co.uk/

Compare prices of bike stuff using this. Although Kelkoo saved me 3 quid on my latest tyre.

http://www.jimlangley.net/wrench/wrench.html

Definitive bike repair/tweaking site.

http://www.slowtwitch.com/mainheadings/techctr/descending.html

Few cycling techniques worth a read.

http://www.preloved.co.uk/fuseaction-adverts.listadverts/sec-Health and Leisure/CAT-Cycling/SUBCAT-Bicycles/0abd8a67.html

And some more second hand bikes.

see you on the cycling+ site chaps