The reviews are generally good but you need to remember that they're based in Hong Kong, so
(a) you'll get clobbered for Customs Duty (where applicable), VAT and possibly a customs handling charge on top of the purchase price ; and
(b) you won't have the backing of UK/EU consumer laws if anything goes wrong.
Many photographic items (e.g. digital cameras) don't have Import Duty on them but others (e.g. flash guns) do. However, in order to allow for VAT alone, you need to add at least 20% to the advertised price in order to calculate what it will really cost you.