Hi Jon,
being in a similar situation like you, we looked in depth at both options.
although more pricey, we had planned on and we'll probably go with grt.
several "key" points:
-grt will bring new hardware, superbright screens, graphics are gonna look beautiful.
-grt had not much of the new software ready for the show, but assuming they port even only the current functionality of the efis1 to the new screen, they're already ahead of many competitors. so anything like 3d terrain etc... will be a neat extra to us.
- grt is actually ahead of development schedule. grt is definitely an engineering driven rather than marketing company, we like that approach.
- grt has a history of many great and regular software updates.
-afs moving map clearly only supports the U.S. with no plans for even medium-term change of policy. the whole company in fact seems to be very "U.S. only" oriented.
-grt is coming up with an optional jeppesen compatibility, of course that'll cost extra but at least you will be able to get data outside the u.s.
-autopilot integration is much much better with grt (tt digiflight IIvsgv) than with afs, which is only working on the basic integration right now (no word on vertical, flight mode annunciator etc..)
-grt has an actual mode annunciator with all the active and armed modes.
-afs screen looks overloaded to me with the hsi overlaid on the pfd, and no chance to configure it differently (2 screen system). in fact they want to patent? that.
-afs announced a partnership with honeywell. they are clearly hardware limited right now, so if they want to bring the user interface up to honeywell (or aspenavionics) standards, then they'll eventually have to bring new boxes which leaves questions about support/software upgrade for the current ones.
-afs currently is probably the better "bang for the buck", gets you a good efis at a decent price, but less features and outlook on upgrades.
-"look and feel" of the user interface with the afs is clearly inferior to grt. single rotary knob versus 2. afs rotary knob drops inputs when turned too quickly (when the screen is loaded/split mode) even at very reasonable hdg-knob turn-speeds. screen update rate is very variable with the afs. function of the rotary knob is set by browsing through a list, pushing the knob. this is clumsy, costs you capacity. you first push the button, visually check which function it is now set to, wheter you want to browse further through the list or turn it now. if you turn too early you'll change the wrong setting. also the list is dynamic, depending on wheter you have e.g. altitude bugs turned on or not. so blindly changing the settings by memorizing sequence doesn't work either.
anyway i've had several "smaller" issues with the afs, which are a dealbreaker to me. it may not appear significant when "playing" with it on the ground, but as a controller, i know what a good or a bad hmi can do to support/hinder you under pressure at critical times.
-grt with 2 screens will give you 4 rotary pushbuttons
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
-the fact that some people at afs were "dissing" grt, e.g. for still having some soldered electronics rather than smd on their board, or using wince as OS etc... did not bring them any aditional points with me. to me that's all fine as long as it works, and it appears to have worked very well. you only need to look at the grt track record, read the yahoo groups etc... if there would have been problems, these would be valid arguments, but brought up like that it's an almost religious reinvigoration of the mac vs pc debate. also that applies to the efis1 base which is now several years old, i assume grt will come up with improvements where deemed necessary.
-we're looking at a 1/2 to 1 year timeframe from now for the panel construction, so timing with the grt will be just right.
that's it for now, maybe i'll have some more flashbacks from the show regarding that debate.
kind regards, bernie