I would suggest that you take the value off the table, as they are fairly close. (I do think a MSF and a Taxi would bring more than a RS, conditions being equal) What do you like to play? If these are going in your collection, then go with what YOU enjoy playing. Pinball is supposed to be fun, and what good is having a machine that you really don't enjoy.. I would much rather have one pin I really like , regardless of value, than 2 I never use. Maybe , if you don't love the RS, make the trade and if it turns out you only like one them, sell the other and put the funds in the "next pin" fund.
Play value is what it should come down to here.
Every customer that has ever come to buy a machine from me has asked, well which one is the best? I always say - play them all, play for 2 hours if you want. The one you want to play again is the best one for you.
My 2 cents
BTW make sure that display in the MSF is good.