I have an mx-890 which I have upgraded from an Mx-780, but I keep seeing mx-890i's out there and am wondering what the difference is between the two remotes. I have a feeling it has something to do with complete control and total control, but am not sure. I know someone here has the answer. It was a little bit different than the mx-780 to program,but, not to bad of a learning curve. I had it programmed before I got the remote in the mail, and it was perfect the first time I downloaded the program. I admit it wasn't too big of a system, but I was proud of myself..my Florida room was an LG 60" Plasma Tv, Marantz 5007 surround sound system, Marantz Blu-Ray, Pioneer DVD player, Roku2, Kodi Box, Spectum Cable box with DVR and my bedroom just a Samsung 50" TV and Bose Accustic Wave radio. No humongous system like I say, but, I got it right out of the gate. And before somebody pops in with the old "how dare I steal software from URC", I didn't. I bought my first Mx-780 from Surf Remotes several years ago and they sent me the software with the remote, and I'm glad they did, because I had no idea about the whole software thing, especially the war with installers and people not being able to get their hands on it, I thought it was web based like Harmony is. Anyway, enough of that, I love the mx-890, it is not more functional than the 780 necessarily, but, it can make things easier and the graphics are nicer. I was just curious abut the i thing.

the "i" means it works on 433Mhz as opposed to 418Mhz.  If you get the "i" series remote, you must use the "i" series RF basestation.  If you aren't using an RF basestation, it doesn't matter which version you choose.

Ok, thank you Duct Tape. In my case then, it doesn't matter since I'm not using RF. Question answered, thanks.

If the OP had been using RF, and had in use mrf350, all they had to add was rfx-250i plugged in along side the 418 rfx250, to control both frequencies with one rf base station.

correct. i figured i'd mention that later as to not confuse things.