Anyone taken advantage of the $49 upgrade to the full Strum GS-2 package?  If so, how would you rate it?

I use the full Strum... Had it for a while.
 
It depends what you want to do. I think that for lead guitar stuff, there are better solutions out there...

I have used the full strum for about two months. I love it.

I also upgraded to GS2 before in was included in Sonar, and like it quite a bit. A huge improvement from Strummer. The 'guitar' editing is quite extensive (I don't edit as the sounds are well done-but for the pick choices) and the effects in the program sound good too, so I use those (compressor/reverb). 
 
I did contact support to find out something I wanted to do that I couldn't find in the manual, and always got a reply the next day.
 
There were several places I wanted a different position on the neck for a certain chord.
I learned how to create an envelope in Sonar for GS2 and program in the fret position I wanted in that particular spot. Many other GS2 options in programing available once I found out how to do this.
 
I'll detail this if someone wants to know.

I would like it if there was a setting to have the strum acoustic chord graphic linger until the next chord is played and remain when the transport stops.

A week in and I'm still on the fence when asked if I'd recommend the $49 upgrade. The Sonar Platinum freebie seems "A LOT" more friendly to velocity. I didn't fully understand the PROMO that clearly stated their was none. I'm very used to velocity "expression" in an instrument and find myself running back to NI samples where I can affect even pitch with velocity. The "Guitar Mode" is significantlying more difficult to use than VIR2's Electri6ity but it's almost 10x the price so maybe it's not a fair comparison. Thus, I'm still on the fence. This is almost like learning to play a new instrument which I'm not sure I'm up to. More to follow ; (