I do C41 colour via my local camera shop which has an Agfa DLab on site, operated by a lady who's been in the business long enough to remember C22. I think she also does E6 and B&W but I do B&W at home and haven't shot E6 in a while. The prices are cheap and she's reliable. £4 for process and scan with download for any format...135, 120, 110, 126, 127. Turnaround is anything from 36 hours to a week depending on how busy she is and if her machine needs spare parts - she often has to perform minor repairs. She's processing films every day and has been rushed off her feet at times. If you shoot 6x9 on 120 or some other format that she doesn't have scanning masks for on the DLab she'll do manual flatbed scans *at no extra cost*, bless her.
I would say the quality might disappoint a professional who makes their living by photography and requires absolute perfection but she does do processing for pros. the scans I get, as an amateur, occasionally have a spec of dust or similar on them.
I've used mail order labs too, nothing wrong with Nik & Trick or Photo Hippo...just more expensive and I usually walk past this shop when I get into town after work. Win-win.