The arcteryx comes in tall for longer legs, but the alpine guide has long legs per size, so either or. I went for these pant since the arc AR only comes in grey now, but they seem pretty much the same! these are wider at the bottom, so might be a better fit depending on your boots.

I would normally say Arcteryx is bigger in the same size, but these are slightly more roomy than alot of the Arcteryx alpine pant.I am 6´and 190lbs and Large fits me nicely, XL for that baggier look.

LT:320N GORE-TEX® 3L ProSV:480N GORE-TEX® 3L Pro That's why LT can be lighter than SV, but SV is stronger than LT The chest pocket zippers are straight on the SV, and slighty offset on the LT. The LT does not have the elastics in the wrist, only the velcro adjustments. Oh, and i think the LT only has one internal pocket, while the sv has two.

The Theta has a collar "inside" the hood, so it is tighter around the neck. The Alpha has plenty of room around the neck, but can be cinched down a bit.(by pulling the hood tight around the neck)

I have both kayland 8 and 9 rigidity boots, and the difference is huge.The eights flex like a heavyduty hikingboot, but the 9 i can barely budge. They are not completely plank, but close (you can flex it somewhat if you really try, but I would say fully rigid.)

These work for me with a G10 MX, as they are rather straight on the top, but they are rather large, so face size does count.Recommend trying it on before buying, but like I said, it works well for me.