Yamaha DTXpress/DTXplorer/DTXtreme

Hi all!
i am sorry to confess that a local store gave the cheapest price for 
a td-20 set even from the newer yamahas and the net,i am going to 
hesitate and buy the second baby. (besides my dtxpress 2 kit)

1)are yamaha racks compatible with rolands'?

2)what kind of problems i am going to face when a connect the brains?

3)does any of you have any setup ideas?!


Thanx for your precious ideas and experiences...
                         
                                                    Atlock