Connected through T3 on Friday and it is really not a very pleasant experience. However, with Flybe more or less enjoying a monopoly as far as intl -> domestic connections are concerned, the choice is between worse and even worse, i.e. MAN or BHX. If you travel from the continent, the only alternative often is KLM via AMS to reach UK regional airports - which often tends to be quite expensive and has its own challenges at AMS.
To be honest, flying in Europe has become a rather unenjoyable experience. I used to do 100+ flights annually until a couple of years ago but have cut back flying dramatically. I use the train much more often these days and if travel is non-essential, I stay put and do video/telephone conferencing etc.