Got to spend some time with a pro and would like to comment on it.
In the past I've had many different Icom rigs, from 735 to 765, with stints running 738s and 746s and 746pros, and have had use of many others over the years. However my main rig was a 706, not known for strong signal handling ability or rx audio quality. I also had a Icom R71A rx rig alongside the 706, with the R71 being a bit better in most respects to the 706 as far as rx performance goes. I have a stereo speaker on the floor in use for the hf rigs as believe it or not I try to enjoy program content as well as music over hf - a good speaker brings out the best in a rig. So there's some background on recent ham rig employment at casa del n0sya.
I've been doing some research on the various popularly priced used hf rigs as a replacement for the 706 (the fan is always on and I hate fan noise), and as I have a small stockpile of Icom xtal filters I decided a 756 original would do well, and allow me to put those xtal filters to good use. The 756 also has that lovely screen, and for those who have never had a tv (specan) in their radio, it's a wonderfull thing to have. Why buy a (used) radio that doesn't have a tv in it when you can for the same price as one that does? Then I noticed in reviews of the rig that all original 756 non pro screens seem to fail, and at $400 or so for the replacement screen I decided that was out. 756 originals often sell for $700, so add in the cost of the eventual new screen @ $400 and other options I feel are worthy (tcxo) and you could buy a proiii for as much.
So I next investigated the 756pro series. I saw many pros going for $1100 or so online, with the proii going for 1300 or so, and the proiii going for around 1500. I looked at the qst reviews on each and decided that for the money the proii seemd to offer the best bang for the buck, low dollar and better than a pro. There seems to be much more similarity between the proii and the proiii than the pro and proii - as far as sensitivity, dynamic range, and other criteria. Another issue is am demodulation. I am a ambc and swbc listener aboutr as much as I'm a ham. Diode rectified am is cheap and works, but it's not the best. The software am demod in the pro series is pretty much the best I've used for a non synchro detector. If you feed it a nice sig it produces nice audio. even reminds me of the clarity and range of my old Halli tube rx, with much better highs than my Drake R8, the pro reminds me of a JRC 535 or 545 in audio quality, something I have always been looking for.
What the pro offers standard that was optional or unavailable on the 756 original model is full dsp demodulation, a much more refined and usefull specan, a xtal oven reference oscillator, and a full color screen that seems to be much more reliable and legible than that of the original 756. Again, my heart was set on a proii and as much as I tried, each proii was sold before I could respond to the ad. A pro model became available suddenly and I decided I would look the specs over betwixt the various pros and decide if I could live with a pro rather than a proii. I found that some of the specs of the pro were better than on the proii, such as blocking and even 5KHz toip dynamic range. It also offered less odd order tx distortion at the 5th order point. All in all the pro series is within 5dB or less of each other in each spec. So a simple pro's not too shabby, and decades more advanced than what I had been using to date.
The pro offered me looks like it just came out of the box, and these things have been around since what, 2002? Anyway the pro came home with me and replaced the 706 and R71 on the desk. The learning curve, wich is very intuitive having learned the ways of Icom with various other Icom rigs, is short save for the most cryptic and least often needed adjustments. A freak about stability, I checked u/lsb on 20MHz wwv after many hours of operating and adjusted the carrier through the wonderfully convenient case opening on the side of the rig, and the pro is now within less than a Hertz of wwv. And it stays there.
So far as to performance, I am very impressed. It reminds me of the 765 in performance, but with that stellar tv screen. I have to say that I feel the audio reproduction is outstanding if not spectacular. An aquantance who doesn't share my love for listening to static (or understanding it) immediately noted how much better the pro sounded than the others. High praise indeed. And that screen! You can easily see distortion on signals, watch as those ufos wizz by, even lightning crashes are fascinating. I never thought a tv in a rig could be so usefull, but now I am spoiled and can never look back. All that being said, yes I'd take a proiii if it was within means, but I do not feel cheated being "stuck" with a pro.
now with true viterbi decoder!