Bernie,
I bought the iPad pro(the large one) when it first came out and have not had a single regret. I use it only for my gig PDF lead sheets. I have not looked at the current versions of the iPad pro.

I use two programs for reading the PDFs. One is UnRealBook and the other is GoodReader. Both do a wonderful job but I have found I like UnRealBook the best.

For my backups I use a program called Imazing. There version I use is free but you can upgrade it if you need or want the added features.

FYI: I now have the Ketron SD40 and am using a 49 key M-Audio controller with it. I like it a lot and it is very reliable. I got the one with nothing on it but what the factory puts on it.

Deane