Here's what I did...
The general consensus is yes, it's worth the upgrade.
That being said, I eliminated most, but not all, of the rattle by doing the following...
I removed the screws that hold the string saddles, and the strings, and swapped holes. That is, I put the saddle screws in the bottom holes, which puts the saddles at an upward angle (by tightening the allen screws) from rear to front . Then I ran the strings through the top holes (which makes them easier to change), and re-intonated the saddles. The string holes are a bit snug for the screws, but they will fit w/o drilling if you coax them a bit.
When you tighten the allen screws in the bridge saddles down to angle the saddles upwards, it will also help keep the allen screws from digging into your palm when you mute.
PS... not my idea... found it on the Squier '51 modder's forum...and it helps alot. If you've already bought the bridge, you could try the cheap fix first, and if it doesn't do it, put the GF on there.
Then you could post your opinion, to help me decide whether to buy the GF or go with a Bigsby. I'm still GASin' for a Bigsby, but haven't pulled the trigger on one yet as they cost almost as much as I paid for the '51. Thanks in advance for the help!
Guitars
Wilburn Versatare, '52 FrankenTele(Fender licensed parts), Fender USA Roadhouse Strat, Fender USA Standard B-bender Telecaster, Agile AL 3000 w/ WCR pickups, Ibanez MIJ V300 Acoustic, Squier Precision Bass,
Amps
Ceriatone Overtone Special, Musicman 212 Sixty-Five, Fender Blues Jr., Peavey Classic 30, Fender Super Reverb, Traynor YCV-40 WR Anniversary w/ matching 1x12 ext. cab, Epiphone SoCal 50w head w/ matching 4x12 cab (Lady Luck speakers), Avatar 2x12 semi-open back cab w/ Celestion speakers
Pedals
Digitech Bad Monkey, Digitech Jamman, DVM's ZYS, Goodrich volume pedal