Hi Jazzphile: Welcome! My Prestige Ultra is the latest purchase and is the most expensive of my 8 rotaries. I prefer foil for overall smoothness and have more of them, but the rotaries are great for beard growth beyond one day.
The Ultra is the best of my rotary shavers. The SH91 heads clearly are superior to the SH30 and SH60 heads I have in my other Philips rotaries. I found a lot of the features of the Ultra, though, were kind of gimmicky, so I shut off the color ring and the light up charging stand. The other features I find useful such as battery percentage remaining, as well as a notification to deep clean the shaver. I usually deep clean after the second or third shave, and I bought extra retainer rings as they could wear out from frequent use.
Though I bought this at a 25% discount directly from Philips, and got a 7-year warranty from them, I have a lingering concern that the head that you pull off to easily clean could become a bit loose after awhile. It is challenging to deep clean the shaver without taking off the head. As other members have recommended, when I deep clean I use dishwashing soap as that quickly and thoroughly takes away grease, lubricating oil, and hair better than just plain water.
Besides lubricating the combs and cutters, I occasionally lubricate the spring that holds the head on as well as the push button in front that allows opening the chamber cover.
Of my 20 shavers, this is the "fanciest" and best-cutting rotary; however, due to the thin nature of foils on foil shavers, the closeness of a rotary isn't quite as close as a foil. Of course, if I get lazy and don't want to shave one day, the rotary shavers do a much better job with that than foils, at least for me. I have gone three days without shaving and it works well.
At almost 80, I'm set in my ways, but when I go to the gym to work out, I use the Philips 1100 plug-in only shaver, or my Remington R50 rotary plug in. I don't want to have to wait an hour at the gym to charge a battery shaver that dies, but more importantly, here in Las Vegas we routinely get up to 115-120F in the summer, and a battery shaver doesn't survive long sitting in a gym bag in the car, especially if you're making a side trip before you go home.
For around $150, the Ultra is an excellent shaver with helpful, easy-to-understand features. Again. the SH91 heads are a major plus compared to other replacement parts.
Finally, one important note. When you look at the Prestige Ultra compared to the regular Prestige line, you''ll see that Philips reduced the size of the platforms the cutters/combs use. This was a tremendous benefit as many people felt the older platforms were interfering with shaving around the nose and mouth.
I'd recommend the Ultra for those already familiar with rotary shavers. Compared to dual-screen foils like the Remington Microscreen, it may not feel as close or smooth, but it certainly is, in my opinion, the best of today's rotary shavers. Note: The $150 I paid for the Prestige Ultra was for the more basic model, with Philips 25% discount. They also added the 7-year warranty which includes everything but the battery. Thanks.