Cross-sync off greatly improves usability

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   When my IFDs were installed in my Cirrus, they were initially set up with cross-sync on. I flew with that for a while, but found the inability to have different flight plans or waypoints in the two units to be frustrating at times. So recently I turned that off, in the process losing the keyboard convenience mode and some other features, but gaining a great deal of extra functionality. I've just completed a big cross-country trip, flying into big and small airfields, and thought I'd report my impressions.
The EXP5000 PFD allows me to select either IFD as the NAV source, as well as having a selection for a bearing pointer and an AUX block that gives bearing and distance to a waypoint. These features were essentially unusable with cross-sync turned on since the two IFDs were always tracking to the same waypoint so unless there was a useful VOR, I could not select different information with those buttons. With cross-sync off, the IFDs operate as two completely independent navigators and allow me to enter different flight plans or direct-to waypoints. I've so far used this for various things:

1) Flying to a destination where I'm either not yet cleared for an approach, or haven't decided if I will need to fly an approach, I can select and activate the approach on the #2 so I get two sets of data (ETE, VSR, TOD) for the two different scenarios. Loading but not activating an approach on the active IFD has the drawback of giving misleading information especially for VSR, since it assumes flying to the destination then back out to start the approach. When I get cleared for the approach I can simply toggle the PFD to the #2 as NAV source.

2) Similarly after commencing an approach if one IFD is still on direct-to the destination I can have the bearing pointer on the PFD giving me direction and distance, useful for position broadcasts.

3) I sometimes need to fly an approach to an airport that is not my actual destination, just to get down through the clouds then track visually to my actual destination a few miles away. I can program the two units appropriately so I have the bearing pointer tracking my actual destination while flying the approach.

4) Using the #2 IFD to try "what-if" scenarios - e.g. if I have a fuel stop planned, what if I skipped that and went straight to my final destination - what's the distance, time and fuel required?

Not being able to copy flight plans from one unit to the other is a nuisance, but the loss of the keyboard convenience hasn't bothered me much - I use a Bluetooth keyboard for the #1 anyway. Some alerts get acked on both with cross-sync on, but I didn't notice this as an issue.

Speaking of alerts, one thing that really bugs me is the "FLTA inhibited" CAS message after takeoff. The last thing I need as I'm climbing out is the system requiring me to ack a message that just says the system is doing exactly what it's supposed to do! I have FLTA turned off on #2, and it also gives me a message, which has to be separately acked (but at least doesn't flash on the PFD.) That particular alert is not helped with cross-sync btw.

One other feature I used for the first time this trip was the rubber-banding to add waypoints. This worked a treat when I needed to follow the coastline rather than flying over a big expanse of water. There were no suitable waypoints in the database, but the rubber-band feature worked perfectly.

I look forward to the time when the software supports cross-sync on without automatically mirroring all flight plan changes between the two units, but in the meantime I'm leaving it turned off. The extra functionality is well worth the minor drawbacks.

Clyde