Some first impressions. First, both of these are not sized to go over cycling shorts. they are generally true to size. If you want to put them over regular padded shorts, expect them to be tight.
Movement. The Bicycle Fixation knicks don't have a gusseted crotch, and bind pretty badly trying to swing a leg over the bike. It's surprised and annoyed me every time that my leg smacks the rear rack because I didn't hike up the pants. This is not a problem with the Swrves - which have more stretch and a gusseted crotch.
Features. The Swrve's have really nice pockets and the reflective belt loops are nice (albeit, hidden under a jacket all winter). The Bicycle Fixation have closing cuffs. The Swrve's have just a seam. It's not an oversized opening, but I find myself wishing that the Swrve's had a drawstring to cinch-up the cuff a little more. The BF knicks have a very nice button arrangement that can get snug - but is a little tedious to get done/undone each trip.
Warmth. I'm not really going to compare them this way. They simply aren't designed for the same temperature ranges.