I do think that living on a slightly dodgy estate has been a blessing in disguise for us. It's classed as a "deprived area" so the powers-that-be are quite keen to spend money on facilities for the community, although not necessarily SN facilities. The portage service is based literally down the road from us and gets a fair amount of funding because there are so many children here with behavioural difficulties. We also have a local Family Project which (amongst other things) runs a short summer playscheme which guarantees that every child gets a place (sorry, Jimjams ). The demand is high so ds1 has been allocated 2 mornings a week for 2 weeks, which will mean a world of difference to us.
The SN services still have long waiting lists. Ds1 will be 7yrs old before he is due to reach the top of the list for the community OT. He also only has 45 mins a month of SALT, although this will increase to approx. 1hr per week when he starts school in September.
IMHO living in a poorer area can be a real advantage in terms of accessing support and services. A lot does depend though on the type of support you need. The services are good if you have a child who doesn't need a lot of physical assistance, eg disability aids, and who is able to be left with other adults relatively easy. We're extremely lucky that ds1 can cope with different carers. Otherwise the situation would be very very different.