Hey Harley, the main difference is they added the fast program change so it changes at pretty much the same speed your MP-1s do. After you install the EPROM, you go to the Global menu and find the program speed parameter setting, change from Normal to Fast. When I first bought my MP-2 I had been using MP-1 for ages and was used to the speed I could change patches, which, as you know, you have to practice and get just right (well depending on the song). The original MP-2 EPROM patch change speed was almost - go get a coffee and wait.... oh I've changed now. I'm exaggerating but that's how it felt. They very quickly released a new EPROM (free upgrade) which had the fast (I would call normal) setting added. Now I'm just going off what we got here in Oz. I don't remember what the original version was when I bought it, but I was probably one of the first here to buy one and the update came pretty soon after. That update was 1.41 as it's still in my original MP-2 and I only changed it that once. So I don't know if they went through a few versions in the US as in, why v1.33
and were there any more versions before 1.41? (e.g. 1.35, 1.40, etc.).
Check if your 1.33 has the Normal/Fast program change setting (in the global menu, i.e. where you also assign an expression pedal to be Overall Master Volume (CC) which I use all the time now). I don't recall the EPROM upgrade did anything else, maybe?? All we know now is 1.41 was the last ADA released for the MP-2.