We moved to Chelmsford from London in October. My DS is 2.5 and we have another one on the way now and the house and space we could afford compared to what we had in London, is amazing.
Chelmsford was a good fit for us, and we looked around at a few commuter-belt towns before deciding. It has a nice surburban feel, big enough that there are plenty of shops, restaurants and a cinema, but also lots of country pubs within a 10-15 min drive so we feel like we're in the country too. The schools are great and it's very green so for me it feels a bit more like 'home' (I'm not from the UK). Funnily enough, the house next door to us was for sale when we moved in, and now houses a family who moved from London also and they felt the same about Chelmsford as a good spot.
For us, we commute into the right part of London also as me and DH both still work there. I'm in the City, so walk from Liverpool St, and DH is in Canary Wharf so gets off the train at Stratford and gets the Jubliee Line in. There are often delays on the train just outside of Liverpool St station on the way in to London, so he tends to be at his desk just before me.
It still definitely is a commute though (although we used to live within walking distance of our offices when we were in London so ANY move was going to mean a commute for us). To give you an idea, we live in North Springfield which is a 7 minute drive in to the station. In the morning, we drop off DS at nursery, park at the station carpark, get the train in to work and that trip is around 1 hour 20 minutes from leaving the house to sitting at my desk if the trains aren't delayed.
Speaking of trains, that is probably my biggest gripe and biggest adjustment. A season ticket is around £3200 (plus carpark if you need one at the station is £1500 a year) and the trains are old stock rather than the newer air conditioned ones. Delay-wise, they're not too bad and tend to be every 4-10 minutes during rush-hours when I use them. We always get a seat too, though there are some that have to stand.
Where we live, there are a LOT of young families and we live in quite a friendly development. The family opposite and next to us on both sides have 2 boys each, ranging in age from newborn to 11 years so my DS has plenty of little friends. I would say it's been easy to make friends, but that might be just because we live in an area where there are a lot of families similar to us in terms of number and age of kids and professions. It's close enough to London to keep up old friendships there too.
Hope this all helps - sorry it's a bit of an essay! Happy to provide more information if you'd like.