That's a hard recommendation to make.
TalkTalk Retail I would not go for, particulary because of its support reputation. On the other hand my neighbour across the road (low usage) has always found the support fine.
Virgin Media is a different technology altogether. Nothing whatsoever to do with the Openreach landline system. They have a cable system to local nodes and extension cabinets, then twin coax feeds underground from the extension cabinets to premises. I don't think they supply what sounds like a block of flats/apartments, particularly new build. Don't take my word for that.
Twelve months ago I would have plumped immediately for Plusnet, who I have been with on FTTC for over three years. However, since then they seem to be having problems that I think are associated with a huge growth in customer numbers and new kit to cater for that.
This affects two things. One is the telephone and ticket support, though the higher-level support people on these and the in-house Community forums are generally excellent and will always persist on hard to solve problems. Normally with success in the end.
The other is that some customers are experiencing poor throughput at times, though most of us aren't affected. Those affected are of course very vocal and post about it frequently.
I myself am affected a little when on particular gateways. My latency and single-stream speedtests can be affected. See
this speed test result. It should be like
this one.
Zen overall are probably better, but considerably more expensive. I haven't used them myself, though I did use IDNet FTTC before Plusnet. I've never regretted the move and have saved an awful lot of money. The only worry I have about Zen is that I've see a few reports in the non-Zen forums here, (I don't monitor the Zen one), where on consumer-level lines they seem to give up remarkably easily when Openreach or BT Wholesale say what amounts to "Tough! The line can't do what the customer says and never could". When it clearly did.
Plusnet forum support would chase it harder. Zen business-level support I expect do.
An alternative supplier you may have ruled out because of the
apparent cost is
AAISP. If you look at their Pick & Mix option, those prices can look eye-watering for heavy use. Until you find
Instead of the normal off peak tariff, between 2am and 6am usage is metered at 1000GB/unit.
by clicking the "How it works" link at the end of the paragraph below the package builder on the Pick & Mix Prices page. If you could fit your downloads into that time span you would be fine., and they don't take "No" for an answer from OR or BTW.
Their problem handling and line monitoring is first class. They claim that they often tell customers they have a problem before the customer realises.
Comparisons.
Just an afterthought, how much do you upload?.