When my HSI needed an overhaul last year I put in a Sandel 3500 instead.
It is expensive, but it gives you so much information that once you get
used to it you won't want to fly an airplane without one.

Ken, what other equipment have you hooked up to it? XM weather, traffic
information, gps, adf, dme... ?

I already had a Garmin 396 so I had weather and to add it to the 3500
didn't make financial sense. I don't have traffic.

I know the Sandel is hooked into the Garmin 430, the #1 NAV (with VOR,
ILS & glideslope) and ADF & DME. Of course it also has heading bug, etc.
I don't remember if there's anything else hooked up to it.

While I was having work done, I had my avionics guy reposition my TKS
controls to the bottom of the avionics stack and had him slave the
Garmin 396 to the Garmin 430; also I had the 396 hard wired for power
and ran the 396 audio through the audio panel.

--
Ken Reed
M20M, N9124X