I gravitate toward emphatic and theatrical acting, so Avery, along with William Shatner, Christopher Plummer, Paul Darrows, and others, all already appeal. Depends on personal tastes. Bakulka might be the weakest, but a lot of ENT was just weak (IMHO) and more "natural acting" requires a good script to begin with. Bad scripts easily get elevated by actors who can turn nonsense into something that's at least fun. And, in general, noting enough wooden actors in life, scene chewers are simply preferable.
And it's easy to conflate actor for script as well. "Emissary" could have been stronger with the show's premise, as opposed to the TOS-like "We advanced aliens do not understand this thing you call love", though the Picard/Sisko meeting made up for it:
Avery carries Sisko's contained anger rather well. Picard's almost on autopilot with patronizing Sisko shows it's all a bit iffy with the writing - or at least an uncertainty in terms of how Picard should deal with Sisko since, 3 years later, Picard surely would have had to deal with such a situation (facing someone who was adversely impacted by Locutus, which is big) by then? But Stewart also knows this episode is for Avery, it's not TNG but DS9 - and if nothing else the end of the scene certainly tells the show's premise well enough (working in a less-than-ideal situation).
Avery certainly nails the conflict, culminated when he gets the chance to respond to Picard about doing his duty and Picard still can't understand
why. I don't necessarily mean due to how Picard was under duress (as Locutus) at the time, and it didn't help that there was no opportunity for Picard to get to admit what happened (PTSD, keeping it buried?) Sisko knows his duty and Picard sounding patronizing about "Oh, well we should just get a replacement" - while not entirely out of character - doesn't make Picard as lovable as the other captains as a result. Kirk fought for his crew, so did Sisko, Janeway, and I'd have to rewatch ENT but I'd bet Archer did too... Picard just acts nasty, then in FC forgets how he got de-borged and guns down his own crew because he doesn't need any numbers, he can save the day as he's wearing a brightly colored cape and flying around.