Never lived in the UK so can't offer comparisons, just a few facts.
I'm living in a duplex in Zaventem, rather close to the airport. Everything was brand new when I moved in, apartment around 80 sq.M., non-furnished, and I'm paying around 500 Euros incl. electricity and heating. Mate of mine got a very nice duplex in downtown BRU, around 90 sq.M. furnished and she's paying almost 1000 Euros. It is a nice place though. But the traffice is murder in rush hours, and I just couldn't be asked to spend upwards of 2 hours every day going back and forth. As it is, I can bicycle in less than 10 minuts
It rains a lot.
Shopping is, in my opinion, very cheap. Beer is fantastic and do try the stronger variety to but you would be well advised to limit the numbers you are drinking.
Fuel is around 1 Euro / Liter.
Cars are cheap, a consequence of which is that there's a shyteload of em on the streets.
Public transport is excellent.
Tax is around 40%, VAT is 19 or 21%.
Public healthservice is excellent I've been told, not yet had any use of it.
Schools are good, you'll get at least tri-lingual kids if you bring any over. Private schooling is expensive though, most people I know send their kids to public schools and are quite happy with it. Kindergarten is free of charge from the age of around 3, in public schools.
It rains a lot.
Downtown BRU is nice, plenty of places to go for food and drinks. Food is excellent, in fact so good I gained 10 kgs in the first 3 months here. Maybe beer had an influence too
It rains a lot.
Belgium, as you probably know, is very conviently located in Europe, with fine motorways going in every possible direction. Amsterdam 2 hours, Paris in 3 driving. Take the hi-speed train to Paris Gare Du Nord from Brussels Midi, it's a 1:25 ride.
CGN in 2.5 hours, HAM in 5, BER in 6. Austrian alps can be reached in 6 hours if your enthusiastic about it, or 8 hours at a more leisurely pace.
With the demise of Sabena flight connections leaves some to be desired, but all major airports in Europe are served by SN Brussels Airline and/or other national carriers. SN has very reasonable fares for monkey class travel. Quite often cheaper than Virgin Express. RyanAir operates out of Charleroi, a 40 minute drive from BRU.
It rains a lot.
Lot's of history here, especially war history if you're interested in that sort of thing. Quite a few decent airshows on the calender too.
In short I like it here, but please fix the weather.
Just a quick edit to ask "English mustard"? Why, when there's an abundance of Dijon available. Will second the bacon though. Food, as previously said, of very high standard. Diaries also very nice. Beers too