I think RFM is better than WCS, and I've owned both for over 15 years.
They are both fun, but I would value RFM higher IMO.
Up until 2010 RFM was generally valued at 1.5X - 2X the price of WCS. More recently WCS has been increasing in value, while RFM has not increased. Mainly because people are scared that it's going to break and not be able to repair it. If both are in great shape RFM is the better game AND at some point it will be the more rare collectible and it will get it's price increase as well. I've seen a lot of beat RFM's that play very poorly though - so you have to consider your games condition.