I have alot of experience with McCormack products and some with the Plinius. Generally, the big SA series Plinius amps will outperform the stock McCormack amps. Those big Plinius's are some of the best SS amps I've heard. The problem is that they are very expensive, very big and run too hot for my taste.
Now, if you're looking at the integrated Plinius, that's a different story versus the McCormack combo. Both are well above average products and you probably would be happy with either for a long time.
My personal recommendation though would be to go with separates and choose the older McCormack models (DNA .5 or 1 with the RLD-1). Here's the reasons:
1. Separates give you the versatility to change preamps. Preamps are very important to the quality of sound, so the ability to upgrade easily without having to change your amplification too is worth consideration. McCormack amps are very preamp/cable friendly with an input impedance of 100k.
2. The older McCormack models are even less expensive and bigger bargains. They are very reliable, so the age is not a factor. They also run relatively cool and aren't ridiculously large.
3. The older models can be modified up to a performance level that surpasses the current stock models and competes with the bigger Plinius's (and most anything else for that matter.)
4. As for intangibles, Steve McCormack is great to deal with. He is located here in the US and almost always reachable by phone if you need him. I like supporting a guy like this. When you buy one of his products, he supports it for the long haul and even updates it to state-of-art levels.
Hope that helps.
