I purchased the 3800 awhile back and had it for one week before taking it in to the service center and then returning it immediately after that. I did experience one clog from it during that week, however that was due to a head strike.
The problem with the 3800 is that the paper handling, to me, was horrible. I was getting pizza marks on the prints from the ejection assembly. I had read Eric Chan's FAQ page and was attempting his workaround to avoid the pizza marks which involved cutting a piece of 2 ply matboard to the exact size of the paper, and using that as a sled to use the front feed, which is designed for thicker substrates. Something must not have been set right because as the paper started to expand from the ink film, it caused a head strike; which lead to a clog of the magenta. A few cleaning cycles cleared it up but the pizza marks remained.
I dealt with Epson Pro service on this issue, which was more or less useless, and they told me to take it in for service, which I did. The tech and I chatted at length and said he would replace the ejection assembly to see what would happen, but we basically agreed that I should just return it and get another one, since it was under 30 days since the purchase.
I returned it to Calumet the next day and picked up a 4880 Standard Edition instead. With the rebate, it came out to a few dollars more than the 3800 Professional Edition. I just decided that I would buy the RIP separately at a later date, since the Epson bundled RIP is extremely crippled anyway.
I am extremely happy with the 4880 it performs like a pro printer should; great paper handling and a vacuum print bed!
The one instance where I did experience a clog is when the paper tray ran out of stock mid job. The printer paused with the print head carriage uncapped and the vacuum continued to run. I probably took a few minutes to replenish the paper, but once printing resumed it was obvious there was a clog, most likely caused by the increased air flow from the vacuum. A few cleanings cleared it up. I won't be making that mistake again.
All in all, I am very happy with how things turned out. The 4880 design is very robust, which I am sure you are aware of since it is similar to the 4000. It drinks some ink every once in awhile to keep the heads clean and open, but nothing that is alarming. It just prints what I ask it to and there have been no issues with the quality.
I wanted to like the 3800... but it just didn't work out for me. The small footprint was very nice and it weighed around 35lbs. But again, paper handling and marks on the print killed it for me. The idea of having to do a "little dance" and feed it paper one sheet at a time just wasn't going to work. I know there are plenty of satisfied users of the 3800 though, it just wasn't for me.
Basically, if you are accustomed to the performance of the 4000 (other than the clogging), I would opt for the 4880.
This is my first post here on this board... sorry it was so long winded. I'll keep it shorter in the future.