Some time player, first time poster.
There have been a few others who have posted on this topic before, but after having played the new version (v.42x) after a year or so playing the older version (v.40x), a few things that I wanted other posters' input on.
It strikes me that the needs/focus system is severely unbalanced.
First, meeting the "decent meal" need seems to require feeding dwarfs food items that in many cases simply cannot be found either in the area or by trade, not by having high quality meal prepared by cooks (which seems to have been the case in v.40). So I keep getting fortresses full of unfocused dwarves who haven't had decent meals so long despite being fed legendary chefs churning out masterpiece meals.
Second, the social aspects of the game seems to be set up rather wrong for v.42. Compared to v. 40, dwarves make friends very slowly but are constantly distracted by being away from friends/family--in a fairly newly created world (how many friends/family have they got elsewhere if they are among the first of their kind!?) I suspect that this is because what used to be just part of what "idle" dwarves did is now explicitly incorporated as "socialize" and other functions. I have not seen dwarves explicitly "socializing" so much, even if they sing, play instruments, and worship a lot. Perhaps they need to socialize more so they can make more friends locally. Now, this occasionally gets conjoined with some weird family/social dynamics that I had seen in v.40 also: sexuality of married dwarves can be, eh, "wrong." I've had occasions where married dwarves have wrong sexualities: asexual or homosexual dwarves in a "conventional" marriage. Odder still is that they have aspirations for raising a family (except the dwarf with this aspiration is the asexual one). In the current version, I've seen an asexual dwarf who is distracted by lack of romance! In another instance, a married but asexual dwarf with a child was distracted b/c of lack of contact with family--except his family is right in the fortress!
Third, the lack of fighting/martial arts distraction might also be a bit wonky: b/c so many of my dwarves were distracted by lack of martial arts, I created enough squads to put every dwarf in the militia, and lo and behold, at any given time, 70-80% of dwarves seem to be training individually even when they are inactive. Either I have a fortress full of fitness buffs or the need for martial arts is so great that they need to spend a lot of time training. They are not purple training so they will do jobs when they are told...but while they are training, they are not worshipping or socializing, and in so (not) doing, they are getting further distracted because they are lonely or because they haven't worshipped yet.
Since I play DF like Sim Dwarf, with a lot of effort going towards meeting my dwarves' needs, I think the needs-focus dimension is a great new feature, but, as it stands, I can't seem to find a balance where any decent chunk of dwarves are not unfocused due to some unmet needs somewhere. Satisfying each need just seems to take too much (if at all possible). I was wondering how others have been dealing with keeping their dwarves "focused."