Machine Mart is quite useful and seems to attract the hobbyist, mechanic and loads of tradespersons. I didn't imagine that lots of professional techs get their hand tools there, but I'm sure some would do.
The quality is mixed and variable. - the "house brand" is Clarke which seems to be sourced from different places (presumably far East for the most part). The small hand tools tend to look like good value but are sometimes disappointing. You really have to judge item-by-item I've found. I don't have any of their socketry, but those that don't want Snap-on (we do see the trucks about), Facom, Beta (my two faves) probably go to Halfords (a car accessory chain - almost a mid-market institution in the UK - who have a "pro" range which is well-finished and lifetime warranted and perfectly adequate for the weekend wrencher (although now mostly metric) - indeed quite a lot of fairly serious racers seem to use Halfords stuff too.
(Don't remember seeing Facom in my local - must watch out next time.)
Machine Mart is good for other stuff - plumbing kit, some building equipment, ladders and scaffolding kits and so on. The jacks, trolleys and axles stands and small hydraulics seem ok and things like parts washers are fine - how they'd stand up to constant daily use I don't know.
The range at MM is huge and very wide - but most of it I don't know enough about to judge it's quality. They have a vast range of power and bench tools - some of it almost looks too cheap to be true, but they have more widely known brands too.
From what some of you guys write about HF, I'm thinking that MM might be a notch above.