As someone who's played from II through V, I'd skip it and go with VI.
I've eventually adjusted to V, but it took a long time.
The 1UPT is cumbersome. I enjoy the tactics it has brought into the game, but there is no way to group units together to move them; not even if they're a settler or worker who needs protection! If you end up in any protracted war, the game will take you twice as long as IV did, just in moving units around, and that is not fun.
Civ VI at least allows you to group worker units with military ones, so you can send them long distance without managing every step along the way.
I think that IV got the balance right between making sure that infinite city sprawl is a crippling tactic, but still allowing you to have a good empire.
V is overkill on this. You can go larger...but many plan their strategies in V around having four cities! As an empire builder, that's just not my cup of tea. Many national wonders cannot be built unless you've built, say, a library in every city you have. Meaning that you cannot expand to a new city until you've completed all the libraries, and the relevant national wonder. Not fun at all.
Civ IV had local happiness & health. Civ V global happiness; which was much harder to manage. Civ VI has ditched global happiness in exchange for amenities, which seem to place a more natural caps on population growth.
The AI in V reacts like it is a game. Do not expect to have any good relationships late in the game if you're ahead. I guess that reflects multiplayer better; but many of us play Civ to enjoy a kind of immersive experience re history, in which you would get on very well with some foreign leaders.
I have no idea yet how this will quite play out in VI. The AI will have two objectives - one known which historically fits the character; the other unknown drawn at random to keep us on our toes. The diplomacy seems much more layered and complex, and you'll have some leaders who do like you when you're doing well in some areas, so I suspect that immersive feel will return a little more, even as the competition stays.
V does bring some great new additions in. The trade routes being attack-able makes the game much more realistic for me. Even on a continents or Pangaea map, you need a navy as a result.
Religions no longer give you as much an idea of who your allies or enemies are in V as they did in IV. Once again, IV's way was more immersive, but in some ways that was a bit of a game breaker...
So if you're anything like me, I think skip V which I rate as being no better than IV and possibly worse; and go straight to VI. If the issues I have raised aren't thing's you'd focus on, then you may as well get V at a bargain price, and come back to VI later on.
But I do think VI is going to be the best one yet
