A typical aeroplane vs. train conundrum:
One Saturday this August I need to convey myself by public transport one-way from Berkshire to West Cornwall (to join rest of family who will have already been under canvas for a week).
Thought I'd try the Flybe service LGW-NQY, the fact I can currently get a flight on a peak season Saturday for about £30 all-in probably tells you something. I'd have to add to that probably about £15-£20 to get me to LGW on the train.
Then I looked at train prices, and found that for a train that leaves Reading on Saturday lunchtime, I can travel to Penzance for £37 in First Class! (or £27 in standard).
Door-to-door (or tent!) times for the 2 will probably be about the same, so I think First Great Western have it.