I use PlayClaw to record, I did experiment with Fraps before making that choice but I found that it had way fewer options and the file sizes were a lot bigger.. so I went with PlayClaw.
To give you an idea of file sizes... around 40 mins of DayZ is about 8.5Gb recorded at 1920x1080 @30 fps. However, this was at night... I wouldn't be surprised if the compression (MJPEG) is no where near as good during the day. With Fraps... I'm betting it's going to be heaps higher cause as far as I can tell it outputs it pretty much raw.