while it may be true I had very mixed experiences with Turnigy (and a lot come with XT-60/90 these days) - but in fact to me it doenst matter as I typically snip off the connector and solder the required one on so I rather look for the price ... I think its quite rare that you can source the pack you want with the right connector these daysThe Deans connector has a lot more electrical resistance than the EC5. Try your best to avoid adapters.
I am pretty sure most UK guys get theirs from HobbyKing. Turnigy is the brand that I hear a lot from UK guys.