I have only the 700 (was I think my second Festool tool?)
I bought the Seneca Woodworking RTS-500 cutting adapter for the 700, and it allows me to cut the smaller mortises with the bits for the 500 no problem. Did a whole bunch of spindles that were less than 3/4" thick for a stair railing.
I haven't run into anything that needed a 500 size domino that the 700 gave me hassle for; maybe there are some specific use cases you would have to use a 500, but i've never run into one yet.
I bought the Seneca Woodworking RTS-500 cutting adapter for the 700, and it allows me to cut the smaller mortises with the bits for the 500 no problem. Did a whole bunch of spindles that were less than 3/4" thick for a stair railing.
I haven't run into anything that needed a 500 size domino that the 700 gave me hassle for; maybe there are some specific use cases you would have to use a 500, but i've never run into one yet.