I have been following these discussions for several months because I have a VFR RV-9A airplane with dual SkyViews, and I want to start IFR training. I almost purchased a SL-30, then a Garmin 255A to do limited VOR/ILS only, but finally had to swallow the big pill and go with the new Garmin GTN-650. I could have went with a used 430W but I felt the new box had nice features, and old electronics are just that, old.
Pilots, CFII's, and controllers I talked to all said that GPS is the future, and if I was taking training, I should be training for all the possible approaches. Old school pilots swear by VOR and ILS, but these systems may not be maintained except at the largest airports in the future. With GPS the smaller airports have usable approaches now with precision vertical guidance.
The saddest part of all of this right now is there is no competition for Garmin in this category, and they are able to charge about double what these radio's should cost. I keep hoping that Avidyne will get their units to market, and will offer some competition to Garmin. Also, hopefully the FAA will modify its regulations to allow certified GPS/WAAS sensors along with experimental avionics to access these approaches.
The used 430W sell on Ebay almost immediately for good money because so many people are looking for a lower cost for this capability. What I fear is that Garmin will pull support of these older units in order to drive sales of its new ones.