Hoping this will get some comments.

I've been riding my bike (2009 Specialized Rockhopper Comp Disc) for about 18 months now. Most of my cycling is on roads or decent quality trails (compressed gravel, hard dirt etc), with probably 10-15% on loose mud and the kind of thing I'd associate with the term "mountain biking".

I'm looking to replace my handlebar grips with ergonomic ones to avoid the numbness I tend to find on longer rides. I've been looking at something like the Ergon GC3 with built-in bar ends, but I've never used bar ends before so have no idea what to expect from them.

Can someone explain in simplistic terms just what difference they make? I get the idea of pulling one handlebar when pushing the opposing pedal to get extra power down, I just don't quite get how bar ends help with that. I'm also a little wary of having a place to hold the bars but where I can't reach my shifters or brakes.