A couple of things.
First, I have the Rockwell Sonicrafter but wish I had originally spent the money for the Fein. I found a tremendous sale on the 180 piece Sonicrafter on Amazon and when it arrived and I plugged it in (had immediate need/use and was waiting for it!) it made this horrible grinding sound. Immediately called customer service who had no idea what it was. After listening to it over the phone, "We" later presumed it might have been a piece of plastic that got stuck between the motor and the housing and screeched until enough was worn away to stop the sound. Customer Service said if it happened again or quit working just send it in.
I know the Fein is expensive, but just the quick change blade system is worth the difference in frustration when trying to switch blades.
I guess my advise is to go as cheap as you can find and plan on replacing the tool (and if you DON'T have to replace it you are WAY ahead) or to save up for a few months like I did and get the best.
If you do decide on the Fein system, there are multitudes of replacement blades at much cheaper prices that are just as good (and in some cases IMHO better) than the stock ones so don't worry about getting the tool with all the extra blades.
As a maybe useless side note, the dust attachment on the Fein works much better than the one for the Rockwell. I did find the one for the Rockwell a great stress reliever as I ripped it off and tossed it across the room.
or maybe that should really be
and then
!!
Second, I guess I have a question about the face frame construction. Are you planning on just joining the corners and intersections or are you planning on creating LONG pieces to make one frame that covers everything? If you are planning on long pieces that are joined, have you considered using a molded / shaped glue joint (just for making long pieces, not for the corners). Personally I like the idea of a locked in joint rather than trusting that I have glued up a half lap joint so it doesn't slip.
OR
Maybe you could get real creative and use door rail and stile moldings (router bits) along the interior edges and at the joints like panel doors without the panels.
Okay, Okay, I'll be quiet and go back to planning the new shop.
Again, just my 2 cents.
Only "we" know where the flaws are hidden, everyone else sees a work of art!
Ben