OK, my orig post is a few months old but I have been flying another B-350 with G1000 and can now make some G1000 v P21 observations. I like the P21 better. I now have 20 hours G1000 time.

With that said (if these can be done, then I have not learned how yet...)

G1000 is not the most "capable" in the VNAV category. The P21 would fly a pseudo-glideslope on a VOR approach, the G1000 will not

No basic Point A direct Point B flight planning is possible. I worked around this by putting (example) KLAX and KMIA at end of FPL and deducing that XXX miles between the two. Then I deleted those entries. On the P21, I would go under Fuel Planning, page ??? 3, and put it there

Radar cannot be overlaid onto route/moving map

TOD doesn't seem to work like the P21. getting it to work properly out of cruise flight seems to be hit and miss

Cannot "draw out the final approach path" aka "make the inbound course degrees big" like in P21. G1000 "Activate Leg" seems goofy

No heading line displayed (when you move heading bug around) on moving map

Entering V-speeds more tedious

With my reduced confidence in VNAV G1000, I am going old-school and using VS to descend.

Chintzy Altitude and heading knobs. No "commercial grade" feel to them. Feel like the radio knobs in a rental car.

Synthetic vision is not "all that." Green and blue screen looks walt-disney-ish and I don't get a pro-pilot feel from it. maybe just me, being anal. shows terrain but we are not talking Google Earth or anything.

ETA at destination only by highlighting a fix, scrolling all the way down to page with destination, then write a note of it on your kneeboard. No permanent "ETA at destination" information anyway on panel or ability to have it

Cannot enter a VOR freq by typing in the ID. "Proceed direct to FUZ". P21 = F-U-Z, enter. G1000 = "can you give us the freq please"

No ground comm

I am sure I will have more later....