I'm now in my third year of membership of a BNI chapter in Bournemouth and it certainly works for me - otherwise I wouldn't still be a member.
Yes, we are expected to act as a sales team for each other, but that is no hardship. We have a brochure of all members businesses, and I pass a copy to every customer. If they then tell me that they need a replacement window, or a gas boiler service, or a new electric point installing etc - I then have a referral for that member.
I get at least a 500% return on my investment re: membership/meeting fees, and I would recommend it to all cleaners. You can visit your local chapter and find out what's involved. It's not for everyone, but it works for me. Pete