Most of my travel where LCC and legacy have been the same price is usually at a busy time of year. So, coming home from university at Christmas when I will have a big bag with me. In which case I will usually favour legacy carriers as the bag will often be included! Further, if I am paying Christmas prices I want to feel like I've maximised the money. So even if it is just a cup of tea and a packet of crisps on BA/KLM if the price is equal I do feel marginally happier that I had to shell out the bucks to pay the Christmas premium.
Sadly my usual journey for a long time was just a short hop within western Europe (1hr15 direct flying) so on a legacy route more time was spent in the connecting airport than in the air, but I usually didn't mind as I am very much time rich and cash poor!
However on this route it would only be at busy times that the prices are level. Ryanair in the off season would charge £14 single, whereas KLM/BA/SABENA would want £300+. Hard choice, even if it does mean trekking to Charleroi airport.
When I lived in Jordan I had to come back at quite short notice for a week and ended up flying Lufthansa, even though there was a better timed Easyjet flight, because Sleasyjet wanted nearly £50 for my bag to be checked in and the price of the ticket was only about £70...