The issues to look out for.
Cracked/broken pcb tracks (same can be said for the MV1, being larger boards they are more prone to this) Also being double board sets the interconnect is something to consider.
Having more slots means more chance of a problem related to less than squeaky clean cart sockets.
Yes there are issues with order of carts, just swap around.
As with any of the boards Nicad battery leakage may be a problem
Because the multi slots draw more current, the 5 volt pins tend to get toasted, this may lead to intermittent boot up.
On the 5 volt thing, its more critical on these boards to have it set correctly. I set mine to a whisker over 5 volts at the board (not the psu)
I have run a couple of 6 slots for several years and have not had any probs (apart from the toasted edge connect) The idea that they are unreliable is a myth imho. Im sure others do have horror stories with these boards, that may be down to bad luck I guess
