Only buy a Subway 8 ( the one with a Nexus 8 hub and rollerdrum brakes ) if you have previously owned a motorcycle.
I had one, until it was stolen.
The cable mechanisms for the brakes are similar to an old drum brake motorbike system. The gear cabling is damned tricky if you need to fix a flat on the roadside.
The rear brake 'reaction arm' is clamped to the chainstay, and you will need to tape round the stay to prevent paint damage. You will also need to replace the plain nut with a butterfly or 'wing' nut to ease dissembly.
Getting the chain slack correct proved an artform onto itself, so I built a chain tensioner device to negate this annoyance.
The gear cable stretches quite a bit early on and adjustment is required regularly.
The Bottom bracket is too low, and I clashed a pedal on the tarmac more than twice.
Has this convinced you to leave the Subway 8 at
Halfords?
But, the Nexus hub was quite good. It would shift up and down any number of gears, pedalling or not, rolling or not. Very versatile unit.
There are other makers who use it - Cannondale for one.