I'm considering exchanging my TVIX M-4000P for the MB100.
TVIX Cons for me:
Takes forever to boot up with the newest firmware, about 1 minute.
RW/FF control is shoddy at best, you can find yourself suddenly at the end of the currently playing file.
Construction - it feels like a hollow 5oz peice of cheap plastic, the front interface buttons are extremely flimsy (they look great in the picture but in person the parts look and feel like they come from those vending machines that dispense the little plastic containers holding a prize lol)
The remote is frequently non-responsive or the units sensor is poorly placed/narrow vision. Quite often I have to reboot the unit several times to get the remote working with it. Oddly enough, the power button on the remote works every time when this happens but NONE of the other buttons will evoke a response from the unit.
Green sparkles using DVI-HDMI at 720p, 1080i (Its not the cable, the issue worsed ALOT after upgrading the firmware but is not worth bothering with considering the rest of my issues)
The fan, while not extremely loud, is as cheap as the rest of it and has rattled and clicked from the first time I powered it on. It sounds more like the fan on my wife's video card did after about 4 years
A friend was not impressed by this issue when I tried to demo the video quality for him. I must have rebooted it 6 times that time, even changed the batteries in the remote. I should mention the M-4000 did not have any network issues.
The MB100 Pros:
Has all of the capabilities of the TVIX and more (as it probably should, it costs more)
Much better build quality, although the form factor of M-4000 is better for my tastes.
The GUI is much more attractive both visually and otherwise, it will display total/current track time for MP3s, for example.
Does not have an LCD display like TVIX, which I consider a plus.
Has HDMI AND
it sends digital audio over HDMI
Has no fan, therefore no noise.
Any cons the MB100 has are the same any other HD streamer has and I can live with that. I went with the TVIX due to overwhelming popularity on AVS.