MTB Chains - advice and guidance please

dicky ticker
dicky ticker Posts: 47
edited April 2010 in MTB beginners
i used to do a lot of road racing many years ago and never managed to snap a chain. i used to change my racing chain every year and pop it on the training bike and never had any issues despite doing circa 4-4.5k miles p.a.

since reading the forums i see a lot people seem to have problems with chains and carry spare links / power links.

have chains decreased in strength / quality or is mtb'ing that aggresive on the chain?

how do these powerlinks work? are they just a toolless method of fixing a chain on the trail?