I prefer overtrousers without mesh linings as these can trap moisture so I didn’t initially view the Helvellyns in a very positive light. However after wearing them on a stormy day out in the Cairngorms I could find no disadvantage to the design as they proved breathable and comfortable. Gore-Tex Performance isn’t the most breathable of the various Gore-Tex fabrics but even so I’ve had no condensation in these overtrousers. I think the two-layer construction with separate lining is probably more breathable than a three-layer construction. The fabric is quite flexible too and doesn’t rustle as much as some.
The cut is quite roomy without being baggy. I wore them over winter-weight soft shell trousers and was able to move quite freely. The long zips mean they can be easily pulled on over big boots. The zips can be undone at the top for ventilation too. Inner pockets can just be reached.
The weight is on the high side and I wouldn’t carry these just in case I needed them. But for cold stormy days when overtrousers will be worn all the time they are excellent.