I had a 68010 in my A1000. There was a small speed difference. Rendering scenes in Turbo Silver I think the difference was only about 4-5%, but there were some demos that ran jerkily with the 68000 and smoothly with the 68010 so the difference was noticeable sometimes. There would have been more benefit from some actual fast RAM (I did the piggyback hack to put my A1K to 1MB), and the combination of fast RAM with the 68010 could have been better again, because IIRC, with the 68010 it was possible to move the VBR to fast RAM.
There were several games that wouldn't run on my A1000 but sometimes it was because of the 68010 and sometimes the weird RAM expansion. I think that Shadow of the Beast was one of the titles that wouldn't work because of the 68010 but it's so long ago I'm no longer sure. I remember going through all my software with the 68000 and the 68010 and I had a table that showed which ones worked, which didn't, and which could be fixed by running SuperDecigel first.
