Lambeater,
If you can say that you are never going to need to cut small strips the Parallel Guide 495717 is fine. The reality is adding the PG Extensions is only $85 more if you buy the kit now... later it will cost you $135. Also can anyone say they won't need to cut smaller strips? Buy the kit you won't regret it.
When I got into Festool they PG did not exist. I bought the MFT kit and love it but it won't let me measure out a 1.5 inch strip without having to add 2.2mm blade cut to 1.5 inches... kind of a pain.
I saw the PG Set in action at Festool event that Steve Bace lead. Until I saw it in action.... I was not sure of the value of the product. When Steve Bace (Festool trainer) showed how to use them, it was a [doh] moment. this device will add value to a project as you an make the same cut many time faster than just using a rail and tables. For a one off cut... the rail is fine. want to cut several strips to form the sides, top and bottom of cabinets.... the PGS will give you better cuts then a table saw, in a smaller space.
The Trick is to set them up correctly the first time and then you are good to go unless you drop them. At this time Festool doesn't offer a case for them...but I hear they are testing some. If you travel to sites you might want to find a cheap rife case that they will fit in to protect them during transportation.
What the Extensions bring to the party is the ability to cut very thin strips without having to add Blade cut off to the measure. you want 1.5 inch wide strips... set the measures and you get them... and you an cut as fast as the saw will go.
Hope this helps.
Cheers,
Steve