I've used Simply Bearings, Bearing Boys and (of course) Arc Eurotrade in the past, have enjoyed excellent service and will continue to use them all.
However, I recently decided to replace the Timkin (taper roller) bearings in my Atlas MF mill after some prolonged 'mulling' (e.g. the usual indecision). Whilst I couldn't detect any obvious problems with the existing bearings, I reasoned that (after 70 odd years) they might not be in perfect condition and it would make sense to do it while the machine was in bits and the headstock easily accessible.
So I shopped around and came across Bearing Basement (in Antrim, NI) and they had the bearings I wanted at a good price discount on both 'Simply' & the 'Boys'. I was a little bit dubious (not used them before) but the bearings turned up within the week and they appear to be the real deal. The savings paid for the Oilite bearings I needed for the other parts.
Regards,
IanT