Alan,
From my observations around the airport, it seems there is a variety of "levels of uses" of an IFR panel. The gent with the -8 across the hangar row uses his IFR capability a lot, and has been all over the country with it. Another nearby gent with an IFR -8 has never touched a cloud...but he stays more local and has the capability in a pinch. Sounds like a lot of guys on the forum get great use from the equipment and the rating, and that's very cool.
As a guy with the rating, but not quite the panel, I'm jones-ing a bit for the capability...FWIW in your survey.
I bought a VFR -6 with the intention of VFR flying only. Upgraded the panel and have dual EFIS, an AP and a 396...but opted for an SL-40. The more I fly the airplane, the more I see the value-added an SL-30 would bring. After researching, looks like upgrading to that, adding a NAV antenna, and maybe a heated pitot, and I'd probably have close to what Steve above has, and I could file /A and shoot a VOR/LOC/ILS if needed. For my uses and situation, that would be plenty, as my goal would be to get in and/or out of a high mins, docile weather situation (marine layer won't burn, etc.) or be able to land ASAP if the airplane or a pax got sickly...akin to what Paul and others called that added confidence factor.
I have a free airline backup, and plan my trips with max flexibility, so that reduces my IFR needs, IMHO...just don't have the need to fly in all sorts of weather, though I respect those that train for it and do. But that's my situation, and I consider myself lucky to have a cheap backup plan.
If I needed or wanted to do even more with the RV and fly "harder" IFR, or had a little less flexibility or fewer options, I'd want all the bells and whistles...IFR GPS (/G), VOR/LOC/ILS (/A), two radios, etc...and in a perfect world, SV (Paul, I covet your panel, along with others'!) Not that ya gotta have it all...it can be done with less, of course...just gotta decide what you need for your comfort and safety.
But if going that route, I'd also be making a commitment to train to high levels of proficiency on all aspects of that equipment. Being IFR-current at work wouldn't make me current in my RV, so the commitment (to me) would mean time and money. I just wouldn't want to press into a spot where I needed everything in my panel, unless I was well-prepared to use it all very comfortably. And even with all the bells, I'd still have pretty conservative go/no-go criterion.
Fortunately (or unfortunately
![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
) my flexibility trumps my budget. But my "have a backup plan" mentality makes me "feel the need".
Guess what I'm saying is (as others have said) equip to your needs and mission (perhaps a little beyond if budget allows, so you don't wish you had later...AMHIK), consider the travel flexibility and options you have, as well as your willingness/abilty to stay current on what you select.
Best of luck...bet it's fun to be considering all the cool gadgets!!
Cheers,
Bob