I had the Endura MT500 and it fell apart on me. Last Autumn Wiggle were selling off the previous seasons Alp X on the cheap so I picked one up for £125.
The quality of the Alp X is fantastic. Zippers, seam strips, fit, wind stop and thermal qualities are all way ahead of Endura. The Alp is also lighter so you sweat less but at the same time it’s thermal qualities are better because it’s Gore-Tex.
The down side to all of this is that when you fall off the Alp rips, whereas the Endura would just scuff. There are plenty of companies out there that do GoreTex repairs but it’s cost me £25 each time (twice now).
I wouldn’t pay full price for the Alp but you definitely get what you pay for (In saying that Endura also seemed to have got over some of the quality issues they’ve had over the last few years).