I lived there for 14 years and only moved out in August. I have a real affection for the place, but there is good and bad.
The Village is way overpriced, the roads are narrow, parking is a nightmare, primary school catchment is about 0.2 miles (and if you don't get into your local school the council can ship you out anywhere in the borough) and secondary education is one of the worst in the UK. All things child related are way over subscribed.
There are some lovely things, the Nags Head cat wall always makes me want to adopt some cats, The Queens is a proper East End boozer in the middle of the Village, the Art Trail is fab and Walthamstow (unofficial) Tourist Board on Facebook is classic. Lloyds Park is great and Epping Forest is on the doorstep. The Victoria Line is super fast into Kings Cross and the overground rail is fast to Liverpool Steet.
I never felt unsafe when living there, and I've staggered home from the last tube a fair few times. You know where is safe and where you should avoid, it is obvious - just don't walk into a tower block estate! Crime doesn't seem to overspill from bad areas into other places.
Personally we left the area because of the houses of multiple occupancy, lack of school places, the councils continual building of social housing on any patch of grass they could find and the real lack of money/investment in the area.
The thing with the Stow is that there are middle class people moving in (there always have been - we did it!), but they are people who have been priced out of Islington, not cash rich banker types - it's brought a steady influx of new people but they don't seem to be bringing money to the High Street - they are probably too busy paying their mortgages and frequenting the few shops in Orford Road (yes I find the Village claustrophobic too!).
Everywhere else it's the same old Pound Shop/Halal Butcher/Bowl of fruit for £1 stuff that has always been there. It will be a long time before the general demographic changes, I was told it was 'Up and Coming' when I moved there in 1998 and I didn't really see that happen.
Gosh I've just gone on a bit! Hope that helps.