It is basically an A500 with 1 meg chip ram and a CD-ROM drive.
Compatibility is fairly good although it will be incompatable with some games that require a full 1 meg as the cd drivers and extended rom chew up some of the ram. A jumper can be removed internally that disables the extended rom so you can access the full one meg... I suppose a switch could be mounted so you don't have to open it every time. You can run A500 games by plugging in a normal external floppy drive.
Another thing to note is that you cannot plug a regular joystick and mouse in unless it is upgraded with an adapter or a hardware modification is done. It should come with an infrared controller that has a button or switch that lets you operate in mouse or joystick mode.
I say go for it.