Here's a suggestion for simplifying the Legacy speed brake installation:  glass over the pockets for them and fuggedaboudem.  Before starting N121J, I noted that the factory demo plane doesn't have speed brakes, and in 70 or 80 hours of flying mine, I never missed them.  Keep it simple, right?  And put the $4K or so into something useful, or another cool toy for your panel.

I find them very useful for a couple of reasons.

1) Expedited descents without pulling off excessive power that will shock cool the engine. If you fly around controlled airspace, this will happen quite frequently. Or what about unexpected turbulence when your in the yellow arc?

2) Scrubbing speed in the pattern. Even with that spinning disc out front, this is a slick airplane that doesn't like to slow down. You could argue that you can always plan to arrive in the pattern at 100kts. or whatever, but we are not machines and sometimes we get distracted with other things (the 172 that just cut you off, or the excessive radio chatter at an uncontrolled airport, etc.).

3) Any type of aggressive flying. I routinely come into the break at my home airport at 199 knots (17 inches, slight decent). Break mid-field, brakes out, MP to 12 inches, flaps 10 at 170 as I come onto the down wind, gear at 135 and start the turn from downwind to final from "the perch" (800 ft. AGL), flaps full at 120, speed break in halfway (or so) through the turn, MP to 13 inches and I arrive on very short final at 100 knots. I coudn't do this without the speed brakes. Sure, I could come in on initial at 150 knots, but what fun is that!?!!

Look, you can argue or discount any of the above, but since we're sharing not so objective opinions, I just thought I'd chime in with mine. I like the "paddles" and use them frequently, YMMV.

Barry