Hi Ian,
I might be able to offer you some comments as I own two of the three on your list.
My first lathe was a Bantam 800 with metric lead screw, this machine is a quality industrial grade work horse, there is very little you cannot do on it. The geared head and screw cutting gearbox make work a pleasure. If you are worried about lack of top speed may I say I have drilled (with care) 0.8mm holes with it.
I also have a Super7B, this is a fine machine, but it must be said it is a “light weight” machine, I often refer to it as my Myford watchmakers lathe, a little unkindly perhaps. You can do an awful lot on a Myford and I imagine half the models on show at exhibitions were made on one. Ask an owner if he would like something bigger and stronger and i would be surprised if they did not yes, if they could afford one or had the space.
I am glad you are contemplating a non Oriental machine, British stuff certainly seems quieter than Oriental machines, some of which have a reputation for being sold more as a kit of parts than a fully functional machine.
To some up, I use the Bantam for most things, it’s bigger and stronger, and I mainly use the Myford for screw cutting Imperial threads, although since fitting a variable speed to it, I have been known to use it in preference the Bantam.
If you have specific questions, ask, I may be able to help.
chriStephens