I live in Colchester. We are very happy here.
Excellent schools, lovely villages, a rural feel but with plenty going on in town, traffic is not too bad, less than an hour into London, nice people, and definitely not rough, low crime, certainly in the part I'm in.
There's a nice feel that there is history. Its not terribly diverse, the vast majority of people are White and Christian (culturally rather than religiously if that makes sense).
The hospital has been in a spot of bother of late but like someone up thread said nobody I know has actually had a bad experience there, its more "bad on paper" I suppose (waiting times in A&E and that kind of thing).
Some nice parks and open areas, and nice things to do locally (I love walking from Dedham to Flatford Mill, that's a lovely walk) and quite near the coast so easy to go to the beach on a hot day or drive to nice places in Suffolk like Southwold or Aldeburgh and have fish and chips on the beach.
Some good Michelin starred restaurants.
Decent hair salons and beauty salons.
40 minutes on a train to Westfield Stratford for some serious retail therapy - just under an hour drive to places like Bluewater if you like big mall style shopping. Obviously the town centre is pretty comprehensive. We don't have Primark though - you'll need to go to Ipswich or Chelmsford for that!
There's a decent Fenwick department store called Williams and Griffin which is expanding in quite a major way (doubling in size at least) which will launch next summer (its open in the meantime though).
A really excellent gourmet food hall called The Food Company if you are a foodie. Lots of lovely farm shops and independent cafes attached to farms and rural places.
Great pubs.
Fairly good public transport mainly busses, and a new park and ride has opened recently.
3 McDonalds 
Quite a few decent takeaways which take credit cards.
Lots of development going on near the new Football stadium, which will include a whole lot of leisure facilities, and a big David Lloyd health club which is opening in a year or so. Apparently a cinema and lots of restaurants in that bit as well, which will perk up the north side a fair bit.
Good stuff for kids, including the leisure centre, which has an excellent leisure pool, and a place called Jump Street which is an indoor place where the floor is all trampolines and they just love it. Several quite good soft play places for little kids.
Its really on the Suffolk border and people speak quite well generally if that's relevant at all. Less happening job wise than perhaps a place like Chelmsford but sounds like you have a job sorted.