IIRC A64 has problems (gurus?) on 020 and above. Magic64 will work nicely on an A500/030, but might be a bit slow on 020.
A64 doesn't ever crash on my 020, but it runs only very few games properly and they must be in C64 format (I use Magic64 to convert D64 to C64). It's great for BASIC programming, but who does that anymore?
Magic64 is MUCH slower and the colours are a bit off, but most games work properly.