Wyred 4 Sound Class D Mono blocks SX 1000 question

I've been listening to the ST1000 amp for years and it is a fantastic amp: explosive dynamics, layered soundstage, velvety midrange, kick ass bass. Personally, I prefer to put my money into expanding my CD collection rather than a new amp every couple of years just to achieve some subjective (?imaginary) improvement in the sound. I would stack the ST1000 against any solid state amp with confidence.

"Obsolete" in what way?  I have a Wyred ST-1000 MKII (and had a ST-500).  They are great amps and as cool as they run it seems like they should last a good long time.  

I was looking at those amps as well. I ended up getting a red dragon audio s500 which makes use of a newer pascal class D module. No clue if it sounds better but it is newer technology.