Our clients migrated from CAM to RMS 1.2 spk2. My advice is what every you choose make sure it has a good datbase (like ms sql server), and you have full access (read and write) to the data.
As for the CAM stuff -- run don't walk.
We just finished a conversion -- it was a nightmare. The CAM stuff is really brain dead circa 1990 DOS stuff. I never understood why my client could not get write access to the datbase from CAM. After looking CAM's retail star it in detail, I understand why -- the DB will break if you sneeze at it.
Retail Star uses a dumb database design, with no concept of stored procs (just an over grown access style database from gupta). Everything is done on the clients; table validation, table updates etc. RMS for example, is server centric, and uses a central database for what databases are good for.
On the CAM stuff, the data you need to migrate is spread all through our their tables, so to migrate the data you need to do multiple joins (and you will still miss 5% of the data). They use a pretty old schema design, that is from the old DOS days. Do the migration on XP. it works the best
After we finished the conversion, everything runs faster, and we never changed out the POS except to add new printers and pole displays. (CAM does not use OPOS drivers).
What every you pick, make sure you look at the database, or have some one look at it for you.
Things are not always greener on the other side. there are some nice UI concepts that CAM has, but that is really about it. we are testing our a wireless pda inventory systems with RMS right now at the cleint to do a cleanup the inventory after the migration.
matt k.