Gosh, TBeck nailed it on the head, there!
Get your supplies of tape, while they last. Stockpiling is not an entirely bad idea, as long as the tape's stored as-is, in a cool/dry place.
I don't think driving the electronics that amount harder [up to 499/GP9] will shorten the life of the components, especially if the unit is in a setup that allows it to properly dissipate heat.
True, probably the bulk of vintage machines are still setup for 456, so it's always a safe bet. 3M made a fairly compatible formulation of everything Ampex/Quantegy produced, F/I Ampex/Quantegy 456 would be comparable to 3M 966/986/250, as would BASF 911. All those manufacturers are out of the reel and tape media business, so the future is tenuous at best, but a fair amount of supplies still exist in tape-specialty shops, nationwide, most of which take orders over the web, also on the phone.
BTW, 3M 996 & BASF 900 were tapes geared to compete directly with AMPEX/Quantegy 499/GP9, JFYI.
I've been stockpiling tape a bit, and I found a tape dealer that 'clearanced' a whopping assload of NEW tape to me at rock-bottom prices, starting at $1/reel! Okay, pick your jaws off the table. I wouldn't kid you guys about that, $1/reel! How sweet it is! Needless to say, I have large storage boxes full of all sorts of reel formats, incl 1/4", 1/2", 1", and cassette too,... not to mention a few DATA-Minidiscs I have for the Tascam 564, plus the obsolete SYQUEST media I have for the Fostex FD-4!
NOTE: I can presently find DEALS on GENUINE NEW QUANTEGY 456-COMPATIBLE MEDIA in PLAIN WHITE BOXES, 1/4" on 7"/1200' REELS, for $2.95/REEL, and there's a LARGE NUMBER OF CASES of 40 AVAILABLE, plus selling as single reels. Living near the LA/BURBANK/HOLLYWOOD media complex has it's advantages! JFYI.
Oh well, point being, that OVERALL the tape industry's gone in the tank, but as of the writing of this memo, ample supplies of tape media are still available, for a finite time only. Stocking up is probably recommended, in the long run.
DITTO, TBeck, that 499 and GP9 may have taken over as the preferred modern standard tape, over 456, and it surely ends the analog-v-digital debate, IMO. However, there's a nominal $10 price bump between 456 and 499/GP9, so that's a factor.
Ditto everything else TBeck said.
