Even in the worse case scenario, from examples I have run, it is better than the 0.40p per mile you get for redeeming for Theatre Tokens, Virgin Vouchers etc.

Some hotels get you up to 0.6p+ because of the way that Kaligo has banded them.

If you get your miles for free from flying Virgin for work then it is a sensible use of them. If you get them via Clubcard or a credit card then you are doing yourself a bad deal.