I for got to add, you should keep the qt wallet and use it normally.
when you want to test, use the new one, but don't forget to backup wallet.dat
to be honest..
it has good and bad on it
personally I like the idea of buttons being on side (even though most don't work still) and the "hiding" feature it has also when clicked again. I like the font itself also as it gives a nice touch on it, BUT
as for the font also, I think it needs to be one colored, not white and black striped(at least I saw it that way). that made it very hard to read,nearly impossible especially on black background.
also would be nice if you could get some nice mouse pointer when on top of text instead of the text "line" pointer.
as for last, after I closed it and was about to run the original wallet,I noticed that it left the suicided open on processes which prevented the original wallet to open till I forced it closed.
these are minor things really on fast peak of it, but just few things I thought I point them out. all in all,I'm looking forward for it to be completed

EDIT: might be also good idea to remove the possibility of negative values on send section as you put the amount through the arrows that pop up there and correct me if I'm wrong but isn't insert typed with s and not c?

On the part of any bugs,haven't noticed any errors so far that could crash the wallet nor do any harm.