What are the weak points of Pass amps and pre-amps ?

Interesting comments in this thread.   I own big Class A amps and really like much about the sound but there can also be advantages to how Class AB amps present certain types of music.  Another thing I have found to matter is whether the output stage is driven by MOSFETs or bipolar transistors, with the MOSFETs usually IME offering a somewhat softer sound that is sometimes described as tube-like.  PASS and BAT use MOSFETs.  I tend to like amps with a bipolar output stage (like my Claytons), although I would like to hear the GamuT 250i monos and Pass' 260.8s both of which use MOSFETs.
I have heard good things about the sound of CODA amplifiers (bipolar output stage) but have been a bit confused as to why they have so many offerings.  IMO they would do better to establish a more concise line-up and stick with it - and offer more monoblock options.  The cosmetics seem a bit dated also but of course that is personal preference.

One obvious advantage of high efficiency and easy to drive (i.e., uniform impedance) speakers is the ability to drive them with less powerful amplification and having a greater choice of amplification for the money. I wish I had considered that years ago but instead now have myself in a position where I need rather large (and therefore expensive) amplifiers. The cost of high quality amplification per watt of power goes through the roof when you need a lot of watts, and you can forget tubes unless you want to spend a fortune on tube replacement.

It would have been nice to be able to use something like the First Watt amps, the lower wattage 30 wpc Pass Class A amps, or any number of under 50 wpc tubed or SS amps available.

Hi Steve, where the heck are you where its still winter? 
It is Spring here in Michigan.....although a brisk 24 degrees tonight 
I think I will go turn on my amps!

Thanks for the information about the 260.8s.  Keep the comments coming since those were sort of on my list to be interested in.