I have the TSO parallel guides for my TS55 and I think it's a fantastic addition to a great tool. My cuts on 8' sheet stock are extremely parallel, easily within .5 mm, maybe even closer (I'm a toolmaker by profession, so I know how to measure accurately). I recently purchased the MKF700 and love it. It you do any edge banding, it's a game changer over manually trimming. I tend to agree with the comments on drills. I have a variety of Milwaukee M12 drills that work very well, so I'm not motivated to replace them. I have the same EC150 as you, and it's my workhorse sander. It was my first Festool item, and love it for it's performance. I also have the Rotex 90 and 150, EC125 with the angle guide for edge sanding, and the RTS 400. These don't get used nearly as much as the EC150, but they all have their place. All these tools connect to my CT Midi, CT26, or CT36, which are fantastic. I don't buy to collect, I buy based on the project need. Good luck on your decision.