I just got my 659 yesterday. Having spent the last two years looking for a reasonably priced remote (below $200) that can control all of my HT gear, I would have to say that I have finally found the remote that controls everything at my fingertips with the simplicity that enables everyone in in my household to use it as well.
I have purchased several universal remotes in the past with high hopes, including the Pronto Neo, the One for All URC-6131, and the RCA-1010. Of all these, I have been using the Pronto NEO for over two years. While it is highly customizable, and will allow you to control any of your gear after doing a bit of programming, at the end of the day, the LCD display becomes quite a hassle. It's like working your HT gear using a PDA screen. Hard buttons are much better. After accepting that drawback, I spent the next two years of use hoping for a substitute that had hard buttons. It is that very reason I wasted considerable time on the RCA and One For All remotes hoping that they could do everything that the NEO did with hard buttons instead of an LCD screen.
Unfortunately, they did not. The Pronto NEO's power resided in its customization, whereas the other remotes I tried lacked capability, which is what makes the remote feel completely like your own. Based on my experience, the only two remotes that I have found that provide both the customization as well as the appropriate number of hard buttons are the Home Theater Master Series (ie MX-700) and the Harmony SST-659.
If there is anyone else in your household that doesn't have the same enthusiasm as you to try and figure out how to do what used to be routine tasks on your remote, I would advise you to narrow down your search for the perfect remote to one of the two. Based on my research, I would recommend the SST-659.
While the MX-700 and its derivatives are very nice remotes, I feel that the Harmony remote wins out in terms of price/performance. You can get an SST-659 for between $125 and $150 including shipping, if you do the necessary research on-line. Ergonomicaly, it feels right in your hand, and the web interface is a lot easier to use than the Home Theater Master software interface. If you want a remote that just works and is easy to program, this is your remote. However, if you are a power user that enjoys programming macros that go to a specific channel or whatever when you turn on the TV, then perhaps the Home Theater Master is better for you.
The only gripe that I would have with the 659 would be specific to people that are heavy DVD/VCR or Tivo users. As I watch most of my televison using Tivo, I would have preferred that they placed the VCR buttons (eg Play, FF, WR Stop, Rec) above the numeric keypad rather than at the very bottom, as they are heavily used when you are controlling a PVR. Overall, though, this remote has enabled me to shelve all of my other remotes for a long time to come.
I would give it an enthusiastic thumbs up.