Have used and sold SBT for the last 15 years. SBT is not a bad product. It works and is documented (maybe not to the level of everyone's wishes). But at least you have all the source code available and they generally do not alter the table structures. I don't think they are going away and as far as the coding - You can please everyone. They have their reasons for coding the way they do. VP 10 is not very OOP but then neither is your fp 2.6 program and I bet it works just fine. So get a demo and see if it fits 90% of what you need and code the rest.
John