Yes, but a bit lazy at times. Keys - 10 years, bass - 5 years and I'm intending to take up Cello and Guzheng in the next month or so too.
Complexity:
Hmm... I only have five or six yes albums compared to all PF, most DT and two of the three TA but I'd say:
PF, Yes, TA, DT
Although, the way Pink Floyd albums from DSofM to The Wall are structured may increase their complexity a little over Yes (such as the chord sequence for Breathe being reprised for Breathe (Reprise) and Any Colour You Like (albeit transposed down a tone), the way that Breathe (Reprise) ends on the same chord that Great Gig In The Sky starts on, etc, and the way that the middle bit of Hey You appears (slightly altered) as a leitmotif throughout The Wall (for example the vocal melodies of the three parts of Another Brick In The Wall), but the frequent reprises of sections in other song sections or other songs entirely for TA and DT make those to higher in complexity both in terms of song and album structure than the other two.
Easiness:
I'll admit I don't often try to learn other people's songs. I probably should but oh well.
PF, TA/Yes, DT
I'm not sure whether TA or Yes would be easier to learn. They seem on similar level, although Chris Squire's lines are moderately to extremely insane at times. Anyone who's listened to Roundabout knows exactly what I mean. DT? Sod that. I'm not even going to attempt to learn their stuff for the moment. There's no damn way I could do that. Pink Floyd? Lots of parts give the illusion of something difficult, but for all its lush orchestration (and I am not PF bashing, as they are one of my absolute favourite bands) the individual parts are really quite simple.
Certainly for the time, Roger Waters's basslines are not complex. They're highly nice, but they are quite simple and very playable, however they are much more melodic than a lot of mainstream basslines at the moment. Gilmour's playing, rhythmically not hard, and the solos are not hideously technical, but man is there emotion there (answer: yes there is). Wright's playing: Not difficult technically, but suits the music well, few solos though, but the few there are are great (compare to Richard Barbieri). Nick Mason: Solid drummer. Not fast. Not technical, but that guy keeps a rhythm, even when he loses a stick halfway through One Of These Days (anyone who's seen Live At Pompeii will not forget this one).
Musical Tecnicality:
Keyboards: Pink Floyd, TA, Moore DT, Sherinian DT, Yes, Rudess DT
That solo on Tales From Topographic Oceans. Maaaaaaaaaaaaaaaaaaaaaaaaaaan
Guitar: Pink Floyd, TA, Yes, DT
Guitar is Petrucci's bitch. 'nuff said.
Bass: Pink Floyd, TA, Yes, DT
Chris Squire definitely does impressive stuff, but I'm not sure he is actually more capable than Myung, after all, the speed of the TDOE bass solo is scary, plus the harmonics and tapping techniques Myung uses sometimes, I think Myung is probably actually technically superior, he just doesn't play up front all the time.
Drums: Pink Floyd, Yes, DT/TA, NEW DT
As it's been said before, Mangini is more techinically proficient than Portnoy, but Portnoy vs. Bruford? Hmm... Bruford is immense, and White is also very capable, but as it was said about when Bruford was touring with Genesis, Bruford did seem to be having to concentrate really hard on the timing of some of Collins's parts (I can't remember where this is said, I'll have to dig out all my Genesis collection, including some documentary DVD, but it's in there somewhere), I can't imagine Portnoy would be having to count the timing too much, though.