Took the North Face to Carn Mor Dearg Arete traverse, and followed the tourist path down (which cut into bog land, with no trail...if you take this route, be sure to have GPS). It was the day before a storm came in, dry, chilly and cloudy. While had a lot of fun across the ridge traverse, would not want to be on it during a rain storm.
It's quite boggie at the base, going up and coming down. Definitely need water proof boots and gear. There are areas of scree fields, but the trail was pretty solid through these. While hiking up to both the Carn Mor Dearg peaks, the rocks are larger, but there are some loose ones (poles come in handy).
Again, GPS is highly recommended, as the trail is scant in various places. Would recommend poles and ability to scramble, if you're taking this route.
Also, if you bring rubbish up...take it back down. It was a bit disappointing to see the amount of garbage left at the top of this peak. Please pick up after yourself (carry in/carry out).