I’m pretty certain they are regulated
2006-2008 Saxo Bank A/S London. Saxo Bank A/S London is authorised by the Danish Financial Supervisory Authority (Finanstilsynet) and regulated by the Financial Services Authority for the conduct of UK business (Registration Number 207519).
alos i use Alpari live and have not had any issues with them, freezing or anything like that - trust me if i did, i would have withdrawn my funds and moved on!
As for reviews i’d just be careful where you read them, if you look hard enough im sure you’ll find every broker out there will have a bad review, all im going to say is from personal exp - no problems with any of them.
I would guess most traders that loose - choose to blame the broker or just about anyone else apart from themselves!