I have only played U8 but I intend to play this CRPG series and I have heard the same sentiment expressed by many gamers who have played the entire Ultima series that for newbies its best to start on U4It depends...
If you want to experience the whole series starting from 1st one - then no, start with 4 and see how games from 1985 are more creative and more RPG-y than 99% of modern titles.
If you want to check this title - then try it, why not? Downloading and running this game will take you 5 secs.
UI is not that bad, controls are easy to handle (well, dialogs are a bit outdated) and graphic is serviceable. Still the story is... weird IMO.
What version are you considering playing? And you should start with Akalabeth.
It's kinda charming in a weird way, but it's a totally brain-dead hack n' slash with zero tactical depth. You can blast through it pretty fast at least. Ultima 2 is actually way worse in many ways.
You make a compelling argument to play U1 when you mention the genesis of things like Serpent Isle. I do want to see the evolution of things in the game world, its just the idea of spaceships in a fantasy setting a little unusual ?I'd also say, give it a try. The "plot" certainly isn't any worse than most AAA titles published nowadays. The gameplay isn't a pinnacle of game design, but if the classic power fantasy of levelling up, getting better gear and killing increasingly nasty things motivates you, it will keep you going. It's worth it for the zaniness of suddenly seeing spaceships and blaster guns intruding into a stereotypical, Tolkien-influenced high-fantasy setting out of left field.
If you're familiar with the later installments (as I was when I played Ultima I ~20 years ago), there's a certain nostalgia factor coming into play as well, such as visiting the island that was to become Serpent's Isle later, or witnessing the humble beginnings of Lord British as a quest dispenser.
Dialogs are for monocled gentlemen. Ghouls are civilized and even the summoned ghoul instead of screaming "braaains" before attacking you has dialogue likeUI is not that bad, controls are easy to handle (well, dialogs are a bit outdated) and graphic is serviceable. Still the story is... weird IMO.