I do recall seeing the interview with Phil Woods where he spoke of the differences between his new 82zul and his Selmer mkvi. By then Phil had played assorted Selmer for 50 years, off the top of my head he played an 82,000 mkvi that Marcel Mule helped him select out of 30 others in 1959? He also had an 80,000 which may have been the one he had gold plated, after which it was never the same for him. Aging musicians typically experience hearing loss in the higher frequencies, and your strength and lung capacity decreases too, such that an objectively brighter horn at 70 might sound like the darker one you had at 30 when you had the wherewithal. There are many recordings of Phil playing his 82z, it records very well with a big clean voice, I like it, but what attracted the 70year old Phil who was running a little low on air at that time, was the efficiency and ease of the machine. The 82z has a great action, terrific response and intonation and a really cooking sound. For me a good 82zUL offers a voice with sizzle which I like for jazz, it is lively and there is some character there, perhaps there is more character in the 82zul than the Yanis.
The Yanagisawa altos are terrific too, and as is mentioned above you can choose what body parts you like. For me I like the silver neck and body, or silver neck and bell combination above the entirely silver horn, which was just too pure for me there are many other options.
There is no way of making an easy choice with all of these great horns,I resolved this problem by at one point having all of the above, and a few others. When I listened to my own demos I hardly knew which was which, it was madness but also fun and I had a full time gig playing alto so they were tax deductable. Now I have just two altos: a S20 308K and a MKvi 75K. Perhaps the hardest horn to get your hands on now is a medium bow late 50s mkvi like the one Phil played, until he gave it up for the Yamaha. I think the Yamaha 82zul horns are fantastic, what is great is that you can just go to a shop and buy one, no vintage horn hunt required, and they are cheap. As for your question about the ease of playing, if you are a youngster and you can spend a couple of hours a day playing the saxophone, the question of the ease of playing a Yamaha versus a Yanagisawa or even a Selmer mkvi is not much of an issue, they are all ridiculously easy to play, if you have an impairment of some kind you might want an easy option, otherwise go with what sounds best.
Phil Woods sounded great on his Yamaha well into his 70s, but when you heard him playing his Selmer, still in his sprightly mid 50s, he was a force of nature. Check out: Body and Soul - Phil Woods 1986 on youtube. I had to remove the link I posted as I was still signed in!