In reply to The New NickB:
If it's a multi-day trip, I wouldn't consider anything else. Okay, a very lightweight jacket might be okay for a day, but what if it rains both days?
I came back from mountains yesterday, we planned three days walk (9 Munros). In the first day only one Munro was ticked off and we decided to camp earlier than we expected. Next morning I found that only my boots (in a group out of 3) are dry to continue walking. I put my baselayer, a warmer fleece and a jacket on at 9:30AM. Higher up, the winds were strong, I had a hail and nearly white-out at one time and it was raining or snowing most of the day. After I came back to lower level, the weather changed a wee bit and I took my jacket off. That was about 4PM or so. I was completely dry with Montane Terra pants, Rab Xiom overtrousers (gaiters as well) and ME Morpheus (very similar to ME Ogre, just a little bit shorter in the back) jacket. And I didn't notice any sweat. I guess some other jackets could have failed as the hail was almost horizontal.
These conditions are not that likely to happen a month later or so, but it does happen (have been in similar weather in May 2013, but without snow).
As I mentioned, I have Rab Xiom pants made from Pertex Shield+ fabric, but this was the first test for them and I can't really tell anything much. I have tried Rab Volt jacket and it didn't feel that reliable. My suggestion would be to go for as heavy-duty jacket as you can afford (in terms of price and weight).