John,
Sorry I didn't get back to this one sooner, but I've been out sailing Chesapeake Bay for the past two days and nowhere near a PC, let alone the Internet.
I believe Yamaha's biggest changes were made with the introduction of the PSR-2000, followed by the PSR-3000 and S-950.
The updates from the PSR-740 to the PSR-2000 were incredible - no doubt about it. And the same was true from the 2000 to the 3000 - lots of exceptional changes, and all highly beneficial for the musician/entertainer/singer.
The PSR-S-950 was pretty much as remarkable is the 2000/3000 changes. I listed them in another post several months ago, and all were in response to what form members on this and other forums have been requesting for a decade.
For example, forum members asked for a color change, back to basic black, believing it looks more professional. I'm not sure about whether black really impacts this image of pro V/S home player, but now we're back to basic black. Of course, the downside was the lettering in the buttons is a bit more difficult to see, but some players have overcome this using white ink and silver felt-tipped pens.
Members asked for a better vocal processor, with a higher quality harmonizer - Yamaha gave it to them in the S-950.
Yamaha next provided players with a better display, one that could be readily seen while sitting down or standing, and even from the side. Yeah, no touch screen yet, but not everyone agrees about touch screens, at least those that are OMB entertainers.
Some folks gripe about Yamaha's key feel, I'm not one of them, though. The S-950 is much firmer than the 3000 by a long shot.
Home players wanted a better onboard amp and larger speakers- they got it with the S-950.
In addition to several new styles, the S-950 also has some incredibly realistic sounding voices, especially the guitars, horns, some of the saxes, woodwinds, and some great sounding, new drum kits - all stuff players asked for and received from Yamaha.
People were always bitching about the Music Finder Directory, mainly because you could only access onboard styles. They fixed that, too. Now, some folks want the MFD to directly access the registrations, but for the life of me, I just don't know why. Most of those players I've run across have never used the MFD - EVER! And, it's not because it doesn't access the registrations. I think, at least for them, it's just too damned much work to sit down and program 500 to 700 songs in a single directory. This, despite the fact that Michael Bedesem and Jorgen Sorensen both have great, free software available for doing this on your PC.
As for the operating system, I never had a problem learning it, but there's no doubt about it that the User Manual is very poorly written. I was a free-lance writer for 35 years and I can assure you that if I were to have submitted anything written remotely as bad as ALL the keyboard user manuals I've read, Roland, Korg, Yamaha, etc..., I would never have been able to sell a single article, let alone make a good living doing so.
As for the upgrades in the Tyros series, I don't believe the big updates became available until the Tyros-4 hit the market. The differences between the Tyros-1, 2 and 3 were miniscule at best. Granted, each had some pretty exciting updates, but nothing an OMB entertainer could not live without, at least until the T4 came along. The T4 vocal processor was a huge improvement over the T3, and some of the other features, which I unfortunately cannot recall at this time, were pretty remarkable.
Now, I seriously thought about getting a T4 for home, and an S-910 for on the road. Then, after making that sailing trip to the Florida Keys, playing my 3000 for some really diverse audiences, and enjoying every minute of living aboard the sailboat and using it was a home base for my traveling music show, I had second thoughts. Hell, I'm going to be 73 years old in October, I can still sail the boat single handed, even in some of the worst storms anyone can imagine, but I'm not sure how much longer my voice will hold out, which is the mainstay of my entertainment package. So instead of putting out $6,000 for a couple new keyboards, I think I'll just keep plunking on those trusty, time-tested PSR-3000s until either they, or I meet an untimely demise. The money will be spent on traveling around the country by both car and boat, visiting old friends, and new ones I've met on the Synthzone and PSR-Tutorial sites.
I don't need no stinkin' touch screen!
Cheers,
Gary