I can second the Video Assist from Blackmagic. It's built tough and the ability to input up to a 4k signal is a plus. I use it primarily as a return monitor for studio and live sports work, but I record the return feed to the SD card for using in demo reels, etc.
There is also the Atomos Ninja Star, but that only has HDMI inputs and records to CFast cards. With batteries, it's about 4 ounces lighter than the Video Assist (8 vs 12oz) but it also doesn't have a screen to check the signal, just LED indicators.
I do live close by the SmallHD offices in North Carolina, and a friend there said be on the lookout for a recorder-monitor to compete with the Video Assist (hopefully arriving at NAB 2016)
