You can also change your xpdr to the GTn750 driven remote version and gain some space on the small stack to to right which has your ADF and xpdr. That way you can put your KX radio there.
On the Ex600 the charts do not disappear if you don't update them; but as others have said, it's closer to eur1,800 than usd200... And that's for Europe, GtN750+gtn650+ex600
I would not want to control the transponder via the GPS as that is yet another single point of failure, but that's a good point re space utilisation.
However the little RHS stack is not something you want to play with a lot, and I use both radios together currently, on IFR flights, allowing four comms frequencies to be set up, or three for the destination airport (atis, approach, tower) and the current enroute one.
Re the Jepp cost, I never had ther slightest doubt the IFR+VFR Europe is nearly 2k. It is the claim that the WW airport taxi charts are $200...
This is interesting...
Discontinuation of Jeppesen VFR+GPS charts and Chart of Aerodromes
(which may actually refer to paper charts only) but I can't find a Jeppview sub which is just taxi charts. Clicking on the Avidyne link on here takes you to a broken link 
They also sell the Jeppview VFR charts in quite small chunks for about €80 each. But I can't see any taxi charts... so can't be sure the Avidyne claim is false.
Oddly enough they still list Flitestar VFR, at €150. Flitestar IFR is there too., This was supposed to have been killed a year ago. I am not suprised they still carry it, given they have no other desktop (i.e. serious use) flight planning app and nothing at all on the horizon.
On the Ex600 the charts do not disappear if you don't update them;
I can only comment on the EX500 and the charts will be labeled as invalid after something like 90 days. You can still see them but have you have no more georeferenced moving map so no more green plane moving on the map.
OK; that makes this yet another great subscription money collection device...
The EX600 still provides georeferencing. May be a bug, don't tell anyone!
I've started playing with the GTN750 trainer and there is no way I would replace my KLN94+KMD550 with it alone. Among many examples, one cannot display fuel data and the flight data at the same time. The Q then is whether the 750 makes as good an MFD as the EX600.
Ps Peter,
i find fuel data not the most important feature for an mfd...
However having looked closer at your panel I can thoroughly advise you the Insight Avionics G4 engine monitor .. It also has an excellent fuel monitor. It has been maybe the best investment I have done.
Like the pop-up 'qwerty' & 'num pad'.
I may be missing something but I don't see a physical keypad. The only one I know of is on some G1000 (or later) versions.
All the new boxes have touch screens and on-screen keypads, which elicit various opinions from pilots. The GTN650 one is a bit small but the 750 one would be fine.
I wonder to what extent one could fit a 650+750 and use the 750's keypad mostly. If one bought two database subscriptions, one could enter flight plans into the 750 and then crossfill into the 650. Presumably one could also thus crossfill into a 430W.
i find fuel data not the most important feature for an mfd
For the MFD, I agree; I display it on the KLN94. The MFD shows just the flight data, during most of the flight, with overlaid stormscope and TCAS data.
The G4 does look very nice. They probably noticed JPI making money on the 3.125" version of the EDM700. However my TB20 had an EDM700 on the Type Certificate and it came with one factory fitted, so I just recently relocated it from RHS to LHS and swapped it for the bigger size unit.
I don't think the G4 will show LFOB (landing fuel on board). For that it needs GPS data. There is another way to get that - Shadin Microflo L. I did consider installing the Shadin Digidata ADC but they have stopped making it.
