I just got my KomputerBay 32GB 1000x today and tested it on the newest build - magiclantern-2013Jun27.50D.109.go.unified.b77a85f7ac68.zip
I did not format the card, just copied everything and updated firmware. Things I've noticed:
1. Benchmark test failed at first. It went through till 5/10 and then froze. Even after turning off the camera the test was still appearing.
2. Later benchmark showed:

3. 1584x1058 @ 23.952 at 1x - continuous, 1920x1080 @ 23.952 at 5x - about 600 frames (I did not change RAW to JPEG and probably some other options were not set properly though).
4. When I half-pressed shutter during 5x zoom (for IS to work) the screen turned pink again from gray (the option in movie menu to automatically half-press shutter does not work BTW).
5. While previewing the raw movie I got
Footer format mismatch, but the preview worked.
6. When I chose lower resolution for 5x mode (1700-something 16:9) which was continuous on my card, the recording stopped after about 100 frames or so twice. Other tests with the same settings worked OK. Some random thing. The buffers went straight to almost full in a second or so.
7. A file was split in two even though it was very small one - RAW is 78.5MB, R00 is 103.7MB.