Thanks so much for everyone who bothered to post.
This has been genuinely helpful.
To whoever was asking if I'd saved 400k from my salary. Makes me feel v proud (so thanks for that!) but yes - I got lucky a few years ago work-wise and earned really well for a few years / saved hard.
Anyway, in summary, I'm not put off buying it I don't think.
Yep, I could get unlucky & get shitty neighbours, but I could get this anywhere.
I think user123346 summed it up pretty well (you articulated it better than I was able to) in terms of my concerns.
I'm telling you now, though, if I had council tenants that were just decent, hardworking people I would be delighted! THEY would be on my wavelength totally.
I may not have explained myself / my concerns very well here, but for those of you outraged, be assured that my issues are not with people on low incomes (I have been there), or people who rent council houses (I have not been there), or people on benefits. My issue is that someone who is able to BUY a house worth 400k probably has to get up in the morning, go to work, sleep at a normal time and generally live a pattern similar to the one mine would have to be. That = harmony to me. There is a greater likelihood that someone who pays cheap rent to a LA may not have to do this to the same extent.
Obviously masses of exceptions etc etc. But I am talking general rules for the sake of trying to make sure my 400k investment is a wise one.
Love the idea of knocking on a few doors, going to do this.
Thanks all.