The M68010 added instruction caches, and processor state saving. I have the Motorola 68k family manuals in my file cabinet of you have specific questions, but overall there is no real reason to bother witht he M68010 unless ou plan on using an application that can take advantage of this.
In regards to the MMU questions: There is no on-chip MMU on the M68010. The original intent may have been to use it with the M68551, but from what I remember, this was not a very practical solution.
You might see a slight speed increase if you use a 68010..you migh tnot. If you do, it will be marginal and only in spefic applications. If you have one handy, by all means pop in it. It can't hurt.
On a side note, you can upgrade an A500 to a 68020 or 68030..I did this with one of my systems some time ago..more for grins than anything else.
Hope this helps.
Cheers //R//
