Personally I don't think much of this unit. They are not very reliable and very expensive to repair. I think you would be much better trying to find a used Aspen 1000
I am looking at that also but finding a used aspen 1000 appears to be about as common as hens teeth, also I,m not tying in an autopilot or a GPS to the HSI just a SL30 nav radio so thought the aspen would be a bit overkill, but if i could find one at the right price i would prefer the aspen. It also appears from the Aspen spec sheet to get the GS function from the SL30 on the Aspen I would need the 1000
PRO model which I think adds about $4k to the new price which would probably translate to about a $2k add for a used one