I have a GTX 260 216 SC that is still running just well in my current system. I have always had it OC to 738/1476/1161 which gives me that nice 1:2 ratio between core and shaders. 24 hours stable on OCscanner, bios volt mod, decent temps, etc etc.
 
Yesterday I tried out the new Precision X which claims to support 200 series, but quickly found out it won't let me unlink or adjust the shader clocks at all. This is a problem for me, because now at 738 core it wants to lock the shaders at around 1550 something, this ruins my previous OC. I have to run a much lower core clock to keep stability with Precision X vs Precision 2.1.2.  I even tried copying my old profiles into the new Precision X as a desperate measure, but of course that doesn't work. I also see that precision 2.1.2 is now considered "legacy" and will never be updated again, bummer. 
 
So does that mean I have an officially obsolete and abandoned GPU now? I will of course keep 2.1.2 archived locally for future use, but would it really be that hard to add shader adjustments back into Precision X for the "obsolete" card owners? I really like precision over other tools but I wanna play with the newest version too!
 
Btw, I'm not interested in getting a new GPU just yet, I only have a single 1920x1200, so the 260 still works well enough for everything I play.
 

Apparently it's not only the 260.  I have an EVGA GTX 285 (1 gb) and I just downloaded the new precision X to discover the same issue.  
I am not planning on any upgrades for awhile either as I can still run 99% of the new games at 1920x1080 almost maxed or maxed.  

Thanks for the feedback, it is possible that we could potentially add it, but 200 series were the last cards to support this. (400 and 500 series were locked and could not be adjusted independent from core)
 
Let me see.

Ok, thanks for taking it into consideration man. I do realize a company can't support products forever, and that 200 series is pretty well aged now. I've been abusing this card for just over three years and it's still kicking.  
 
 

yeah separate shader control would be nice since these cards fold better with higher shader clocks.

I'd like to see shader clock adjustable for the 200 series, I have a GTX 296 1st design with 2 PCB's, it was already OC'd a td above standard 295 specs, core 594, shader 1296, memory 1026.
I have always OC'd it when playing graphic intensive games to core 650, shader 1400, and memory 1100, but I cannot adjust the shader values anymore unless I use 2.1 as the others mentioned.
I paid 500.00 plus 50.00 expedited to get this 295 when it came out, I have opened it up and replaced the paste with AS5, and upgraded the thermal pad material, and the card runs a little cooler than it did brand new, and it OC's like a champ, so I'll be waiting to move up to a 600 series, I may actually hold out till the 700 series, because at 500.00 I'd like to get as much usage out of the card as possible.