The problem with BT (notso) HotSpots is:

1) you have to share airspace with a lot of other Wifi routers in an urban setting. It is sorted by allocating channels but IME there can be 4 or 5 routers using the same channel, despite some channels not being used - maybe out of range of me, but competing with routers that are visible. I guess.

2) You have to share bandwidth with the owner (renter) of the router and they should get priority.

3) BT know you are a "parasite" so may be controlling how much you use.

4) BT (notso) HotSpots switch routers or decide to curtail you in random ways. Forcing you to Log-in again.

All in all a poor service given their bragging about millions of (notso) HotSpots. But I can get 144 Mb WiFi often, and nothing on internet. But when the router owner isn't watching TV (assumed) I get a very fast upload. My philosophy is to be happy using BT for free as payback for when they cut me off without warning. (Dot get me started).