It's cousin, the 15-133, has 8 devices with 8 buttons. Inside, the two models are identical, but devices 6, 7 and 8 have no physical buttons on the 134. But these are still useable in the PC programming software. You program it to activate those devices with some other button. For example, DVR could be HR21 #1 and shift-DVR could be HR21 #2, where shift-DVR has a macro with device6 as the only step. Then I'd just put the other two DVR's on the SAT and AUX buttons. I actually have 10 devices on my 134 at the moment using an advanced technique called multiplexing. Discussion of that belongs over at the hifi-remote.com forums. It does have a JP1 connection (JP1.3 to be precise, so you'd need a JP1.2/3 cable, not JP1 per se). So get THIS cable, THESE drivers, download the IR and RM software, the config files HERE, HERE and HERE, and you'll be in business. I admit assembling all the required parts and pieces is a little tedious, but you only have to do it once, and it's worth it. Unfortunately it is impossible to add JP1 to your remote. URC has a completely different architecture and is not JP1 compatible at all. To make things even more confusing, there are many JP1 remotes with a model number that begins with URC, even though they're not made by URC. There is some learning curve to JP1 programming, but thousands of people do it, and it works brilliantly. It's also much easier than it was a few years ago thanks to big improvements in the software. It's certainly not as easy as harmony, but much more powerful, and much cheaper. Harmony hides all the nasty details and gives you a slick interface, which is great. But if you want complete control and flexibility on the cheap, JP1 is definitely worth a try. If you're not comfortable programming though, it's probably not for you.