There is a conveyor at the end in the Xerox videos...Feeding is not really the issue with Xerox if you have the HighCap feeders, it is the stacking that has to be babysat. Maybe someone make a envelope stacker.
You're not really comparing apples to apples with these two models based on speed and duty cycles.
The Ricoh C7210 is the model that most closely compares the the Xerox 3100 and KM C1100 (now KM C6100). The Ricoh 9200 is more on par with Xerox's Iridesse or KM's C12000/14000 series. As for reliability, this question is often asked in the forums and most people only have current experience with their own brand, so they can't truly speak to how reliable the latest model is of another manufacturer. These days, I think all of them are pretty solid based on talking to other shops in the area.
They all offer some form of operator replaceable unit/maintenance program if you ask for it. Service response is going to depend on your location - how close are you to the home office and parts warehouse is big factor.
Since you mentioned VDP printing, then RIP'ing power must be a consideration as well. All 3 brands offer the Fiery controllers, and usually offer 2 options: fast and faster. Make sure you're getting quotes on equivalent RIP's when getting bids. All 3 can also run envelopes.
You mentioned color stability across the machines. This is always a challenge for any brand. On the newer version of the KM's (C6100) they now have the IQ-501 which offers an in-line spectrophotometer and high speed cameras to constantly monitor color and alignment on every sheet. Xerox has something similar to this - I'm not sure if Ricoh does. If color is really critical, then I'd suggest getting Fiery's Color Profiler Suite along with your RIP's.
All of the brands offer similar in-line finishing. If you need something specific, it's best to check the specs on each vendors version of the finisher.
And lastly, you mentioned up to 300gsm...all of the models mentioned support at least 350gsm, simplex or duplex, some do up to 400gsm.
3100 was a Ricoh fax machine like 20 years ago.FWIW, while I'm sure most people could care less about what model number ends up getting assigned to a printer, those of us dinosaurs who have been around a while sometimes get a chuckle out of it. The 3100 for example was also the model of small floor copier Xerox had in the 1970s and wasn't terribly reliable. The 9200 was also a copier in the 1970s, the first high-speed b&w copier that had no peer, at the time. It was also featured in the movie '9 to 5'.
(We'll now return to your regularly scheduled program..)
I have 2 3100s and an Iridesse, feeding has never been a problem, getting the envelope to pass all of the way through the machine is a real trick. I have a Canon 710 and 910 exclusively for envelopes. The more I read these threads, it really makes me wonder if I'm being short changed with the caliber of field techs I have in this region.Xerox sells a very high end envelope feeding system for the Versant line. If you have 10+ Versants you can easily justify the expense of a single machine that has a dedicated envelope feeder. I saw it in Chicago last year, it was very impressive. I know Brian Segnit has an account on this forum. Is there any way to mention him to get his attention?
Advancing Productivity and Service Delivery
Enhancing the Print Customer Connection (Part 4)
Read All About It