btw I've actually tried using Legacy for a good while, and eventually I stopped using it for a few main reasons
one of them was because there's a massive space in the post content area which doesn't go away, like, ever. I suppose it's because I have signatures disabled, but I'm not willing to enable them again just for the sake of the post layout being bearable. I disabled them in the first place for a cleaner browsing experience, but since most people make shorter posts it's just annoying to deal with.
even in the case of longer posts, it stretches out the post flair unnecessarily. on standard, it doesn't matter whether your posts are long or short, it doesn't really affect the post flair at all, because the flair isn't part of the post content area. but in legacy, it seems to act like it is, so it stretches depending on the length of the post so that's also something to take into consideration when designing flairs when can be kind of annoying depending on the flair that you have.
so not only do you (generally) have to design flairs that don't totally look like a mess on both post layouts, but you have to be mindful of how it looks when stretched out as well if you ever decide to make a long post.
also while I browse PC fullscreen i can imagine if it may be annoying for half screen people to browse, doubly annoying if they have to read a long post while not browsing on fullscreen. the legacy folk can argue that there's a huge unnecessary space in-between the username/usertitle and the user information, but you can double that space in legacy pretty easily if you cared enough to because you can stretch the post flair as long as you want.
I do respect whatever preferences people have at the end of the day, though. I understand how legacy peeps like the more condensed information because it looks neater that way. but the little nitpicks are something that I can't deal with orz