Well, I had about two hours to play with it last night (I had Laird's document in hand). I plan on making a day of it on Sunday to work out the loop and complete the setup properly. I have no experience with the original G and I'm not using a M4. However, my initial impressions are good. I mainly went through the document a few times and tried to balance levels. I didn't dig into editing the effects much.
The front end is good, very good. Using the insert out, I went back and forth between the G input, direct into the Mod50 and through a GCX. I could not hear any difference in the sound quality between plugging in direct or through the G System. Initially, the BB had an audible click when its loop was engaged. But, a re-read of the input gain setup and shutting down the boost function cleared that up. I like the compressor alot. I didn't get into the filter to much. I think I want to dedicate it to the whammy effect and keep my dunlop. But the G's wah worked well and was clean and responsive to my movements. My verdict on the front end is that I think it can replace the GCX, voodoo power, Keeley comp and maybe the Dunlop Wah for me.
I've read all over the forums and web regarding the serial loop in the Mod 50. The hardest thing for me to get past is the channel masters, because I feel like they add so much depth to the sound of my amp when they are cranked up (probably the same for the M4). I am also very partial to the MPX1 that I use in the parallel loop. However, I really want to make the G work properly because it really simplifies the setup and removes alot of weight and bulk to my rig. Out of the box, the G sounds bad in the loop (so did
the gmajor2). However, towards the end of my session, it started to make more sense how to setup the gain structure properly. With short balanced cables, there was no hum outside of my guitar pickups and his document helped get most of the tone back that I felt I lost when I turned down the preamp gain. I just have to get over the fear of cranking the master volume of the Mod50 to 7 or 8 in low power mode to make of the volume. I read his document twice today and feel like I have a real game-plan for Sunday. So, I'll reserve judgment until then.
Three things I didn't like... The presets are wet and fairly uninspiring... But, YMMV and obviously, we are all going to tweak the effects to high heaven anyway. Unlike something like an Axe, you can't send different effects to the different parts of the unit. So, if you want to use a tremolo, it can't be out front (for example. This is the same as the silver G and according to the white paper, it's like that because the unit's effect blocks are hardwired, not programmed. The tuner only mutes the outputs, not the insert. So, if you are using the 4 cable method and you want silent tuning, you are forced to use it serial. Perhaps the killdry takes care of this for parallel loops. But it wasn't something I tested.
My plan for Sunday is to setup the presets to switch channels on the amp via midi, properly setup the channel masters with a voltmeter and the white paper, introduce a line level shifter if need-be and go back and forth between the 4 cable method and the 2 cable method for modulation, while keeping the mpx1 in the parallel loop for reverb/delay.
Just my .02. Hope it helps