Hi Darren, as i've already said i'm no expert or trader so I can only offer my personal thoughts and experiences on the compression and Linebreak are the only stuff i've owned of this type but like most I don't really have the spare cash for the Skins compression wear I originally wanted!! 
The tops are really good and well made and obviously fit well, I would deffinately say check out the size chart before you order too. The 1st time I wore my kit the top did ride up a little but once pulled down properly stayed in place. I've since ran in just the suit and a vest in cold and even snow and was surprised how comfortable I was temp wise and did'nt even feel the cold till I stopped running but be warned, get wrapped up soon after as once I stopped the shivers set in quite quick!! 
TNH, I originally wanted the compression wear because I suffered with achy calves after my longer runs and was quite dubious too about the claimed gains/benefits of compression wear but having worn it on a few 10mile+ runs I cant speak highly enough of the long tights!! My legs felt better than they ever have after and I could actually walk straight and proper the day after (I had walked like John Wayne previously
), I personally wear them to run in and then for say for an hour or 2 after and then just bath/shower as normal. The tops are less beneficial muscle wise I find but having said that I did do my longest run recently (12 1/2 miles) and did'nt struggle as much and kept up a decent pace, not sure if that was down to the top, me or my fitness level improving slightly!?! 
All in all I took a punt for the price I found and thought at least i'd have some cool looking kit even if I did'nt benefit physically!! BUT I HAVE and cant speak highly enough of the Linebreak kit and will be ordering more come the spring when i'll need a shorts and vest set. 