52 mile round trip for me which takes about 1hr 45 each way. Not the most interesting route but it's relatively quiet, has a couple of cheeky hills and it does take in some some nice countryside until I get to Bristol. I find that mid week I do start to get tired and the Mrs starts getting upset when I fall asleep at about 2100. I can always chuck the bike in the car and make it 16 miles each way but driving the last 10 miles doesn't actually save me that much time. I've cycled all year around, in some horrible weather, and after a couple of rather expensive services at the LBS, the prospect of buying a commuter is looming large. The Mrs is almost buying into n+1, as opposed to being firmly in the n camp.