Your basic comment is right, EN48. The SAGEM system is really a fairly standard depiction of traditional flight instruments. However the advantage of the SAGEM system (as in the STCs on the 407 and 206) is that it puts the engine indications "under glass." There is an option on the SAGEM system for a rather nice map capability, but they have yet to present it in an "SV" (synthetic vision) format.
It's good to see that the Sagem influence is beginning to yield results. As you may know, Sagem bought the old ARNAV company, and their prior glass implementations were mediocre in things like anti-aliasing techniques, etc. (the stair case effects you get curves, etc.) When needles and horizon lines were actually in motion, the effects of the "lego-block" depictions were really distracting. The new stuff seems to be a much better calibre.
The Chelton stuff is primarily EFIS. Chelton has worked a couple of programs to put engine "under glass" (most notably the defunct Bell 417) but at the moment doesn't appear to be there yet. They also seem to have dropped development of their larger 6"x8" displays which they stopped showing at trade shows soon after the 417 was cancelled. The SV (synthetic vision) presentation, and the ability to bring in TCAS and present FMS routing in lay-down and highway-in-the-sky is still what sets Chelton apart. The people who like that sort of thing, love the Chelton displays (my read has been about a 50/50 split.)
I noted a marked drop, however, in Chelton systems being displayed this year at HAI. I wonder if they've over-extended themselves... they were getting into everything for a while including writing the display software for the Eclipse jet.
As far as problems with the Cheltons go, the issues I've heard of are primarily in the supporting equipment. Their earlier generation stuff had a Cross-bow AHRS that has the magnetometer (flux valve) for heading built in - which means you have to mount the unit in a BAD spot for AHRS performance in order to get the magnetometer to work - or if you got the AHRS to work, the magnetometer wouldn't.
I heard of several installations where they eventually had to replace the AHRS, either immediately, or later when they added some piece of equipment near the AHRS that started creating problems.
The brand new generation Chelton displays have ADAHRS built onto the back of the display unit with a remote magnetometer. To me this is the WRONG place to put an ADAHRS. There are lots of problems that come up with panel-mounted helicopter attitude systems - so why would you voluntarily put one there? In traditional mechanical indicators, there has been all kinds of anomalies that pop up as a result of instrument panel vibration change. Helicopter OEM will generally pick through several models before they find one that works in all their configurations. Sometimes changing skid height or hanging something new off the belly will send what was a perfectly well-behaved attitude system tumbling in a certain flight condition. For a helicopter, if you can, you want your AHRS (or gyros) mounted someplace solid. Panel mounting attitude sensors is a last resort.
Also adding the ADAHRS to one display makes the units non-interchangeable (the old ones were interchangeable.)
But back to Chelton's SV....Keep in mind that Chelton is the "first generation" SV (Its still all brown below the horizon - and it doesn't depict lakes, etc.) It happened to get picked up by a lot of Helicopters and STCs a few years ago. Universal systems made the breakthrough for what I'd call the current generation SV when they TSO'd their system (announced NBAA 2006) which brough a whole new level of detail to the SV depiction. Then you could have blues, browns, and greens coloring areas below the horizon so you could depict lakes, rivers, terrain features, etc. (something useful for those of us who don't operate in mountainoius terrain.... you notice they always do the SV demo over Denver or Boise... not Kansas)... In any event Honeywell and Collins have now followed and they have some sweet systems. I have yet to see them in a Helicopter, but I know they're working it. My favorite is where they blend SV with EVS so you get a real-time FLIR image imbedded in the SV context (Since deer on the helipad are not normally part of the SV obstacle data base) ....but I can tell I've probably "geeked out" too far by now.
Enjoy your new toy, EN48...