Superb, consistent performance without the need to tweak, adjust, fiddle or otherwise drive myself nuts. Also, you can easily adjust the pump OPV without any disassembly.
Negative Product Points
Well, it's hard to find any, really. The one that many others have pointed out, the detachable "controller" bothered me mentally before I but the bullet and ordered. However, it has been sitting in a drawer for most of the six months or so I've had this unit and I have only taken it out once. Aside from that, I haven't got any real complaints or negative observations.
Cup-after-cup of consistently fine espresso. I have not had to do any tweaking to speak of. On one occasion I found it needful to trim the pump pressure and was grateful to find that this operation could be carried out without disassembly of any kind. On arrival I opened the box, filled the reservoir up and have been making super coffee day-after-day ever since. Better yet, it got the vital "Wife Seal of Approval " award. My usually gadget-averse spouse uses it with pleasure and agrees with me that the cost and diminished counter space were well worthwhile. Shortly after receiving it, I plumbed the unit directly, an easy enough bit of work once I found out how to put a hole through a granite counter-top so my life has become simpler yet. It turns on in the morning, and I run it all day.
In selecting this machine, I was constrained by my requirement for a double-boiler system and a desire to keep the counter-top real estate consumed to a minimum. The other serious contender for this purchase, the Vibiemme Double Domobar required more counter depth than I was willing to sacrifice and had an absurdly small water reservoir. The rationale for this was something about "stale" water, but this made no sense to me versus the hassle of refilling it more frequently. The capacious reservoir in the R58 is easily refilled on the fly and holds a lot of H2O. It's been a while since I have used the reservoir but I as I recall I did not have to fill it more than once per day. Some have pointed out that the drain pan doesn't hold as much water as they might have liked. I can't say that this was ever an issue for me, but once we plumbed it in, you forget about adding water and emptying drain pans. It never fills up, drains freely, is easy to remove and clean once in a while and requires zero attention. I have a whole-house water softener so no special equipment was required for this work aside from the parts that came with the machine and a few plumbing parts easily found at Lowes.
One interesting point: I was concerned at the very long warm-up times people reported for this machine. It's not true. It takes no more than ten minutes from power-on to "ready to brew", certainly not the 45+ minutes I was led to expect from some other reviews and comments I read. I have never managed to outrun the hot water. My wife even uses the dispenser to get water to heat oatmeal! You've got all you can possibly use for brewing in a home environment, and plenty of steam. I am running it on 120 v.
Speaking of steam, my R58 came with two steam nozzles. I am not certain whether this was a unique add-on for a purchase from Chris Coffee or not but I did end up changing to the "extra" 0.9 mm tip and get better steaming from it.
I made this purchase from Chris Coffee Service. I had never purchased from this outfit before I bought the R58. I spoke with Chris briefly a few times prior to ordering, but you never really know an outfit until you have pulled the trigger and see how things work out. I am now a loyal and happy customer of this firm. My order was delivered immediately, so quickly that I had to ask a neighbor to grab it for me as I was out of town. Everything was in perfect condition (the shipment included a Mazzer Super Jolly as well) and it's hard to find much to say when things go "right" as in "right out of the box. I had the R58 up and running in a few minutes and I haven't looked back. I have since made several other purchases, including a really nifty Dynamometric Professional Tamper, a great item. These people are a pleasure to deal with and are always courteous and helpful on the phone.