Avionics: GMA-240 replaced with GMA-245.

I replaced my GMA-240 with the GMA-245.  I did this because of some of the features the latter includes over the former.  Below I only list those of interest to me - it has additional features not included on the GMA-240:

• Auto-squelch.
• Independent music knobs for pilot and co-pilot. 
• Integrated Bluetooth.
• Great for music from my phone and for phone calls.
• 3D audio.
• Clearance recorder and player.

GMA-245

GMA-240

Though I much prefer it over the GMA-240 I am disappointed with a few things about the -245:

• It does not include an option for "button tone press".  So when you press buttons, you don't get an audible indication of having done so.  I asked the G3X team to include that option in a future firmware revision.  Based on their response to me, I'm not expecting them to do it.
• The photocell-based auto-dimming is poorly calibrated.  At night time, the announciator lights are not discernible.  I asked the G3X team to consider adding an option to adjust its sensitivity.  Based on their response to me, I'm not expecting them to do it.
• It is unable to do a software update via the SD card.  Garmin's G3X support group can provide me no solutions other than to repeat to me what's in the documentation then suggest taking it to a dealer.  My plan is to have my intercom updated in a friend's plane who has a G3X system (the G3X can update the 245 through the CAN connection).

The GMA-245 is not pin-for-pin identical to the GMA-240.  It will work as a direct swap, but some inputs will be remapped to different ones.  The remapped ones, specific to my aircraft,  are shown below (240 to 245).

• Alert 2 → Alert 4
• Alert 3 → Alert 2
• Alert 2,3 Audio In Lo → Alert 3,4 Audio In Lo
• Mute* On Com Tx In → Discrete 6 Input* (Copilot ICS Key)
• Com  Swap* In → Discrete 4 Input*
• Button Press Tone Enable Hi → Reserved

 Wiring maps for both, as connected in my aircraft, are below.

GMA-245 (installed)

GMA-240  (removed)