What could we expect from a new owner?

Tan is pretty rich, but there are richer people out there - however, we are currently putting in about the maximum we can under FFP.
So an even richer guy would have to find ways around that OR just take a gamble on going up and spend a lot to achieve that - that's a possibility, but there is a level of risk doing that unless they are SO rich it doesn't matter.
I don't think any of the names being touted around as in the market for championship clubs are likely to be able to blow the rest of the division out of the water, so we'd likely to be in the same boat or worse off if we got a new owner.

Of course you also have to consider how well you spend/invest that money. It would be difficult to argue that under Tan we've invested his money well. We've had parachute/premier league money for almost a decade and the squad is in a much worse position than it was before that began.
I do feel that as a club we've learned some lessons along the way - and we are at least currently trying to set ourselves on a better path with things like securing a regular pathway from the academy to the first team - that will mean that we don't need to spend as much in wages or transfer fees to fill the squad - and eventually we will hopefully be able to sell some of the academy players for big money if they continue to improve.
Additionally the transfer strategy seems more sensible of late - talented prospects from lower leagues who might increase in value, free agents and loans.
Are there owners who could do a better job than Tan and the leadership team are currently - absolutely yes. If you look at the likes of Matthew Bentham he's driven his clubs forward without splashing a huge amount of cash. However for every Bentham there are several others who aren't as good - you only have to look at some other teams in this division to see how much money has been wasted elsewhere not just here.
Will this more sensible approach from the club continue? who knows - I'd like to think so, but I wouldn't rule out us having a bad run at the start of next season and the club bringing back Neil Warnock or something else as ridiculous.
On the other hand exactly the same could happen with A.N. Other manager.

I'm happy to see Tan stay currently if he's got the financial resources to ride out the covid impact to his businesses. And hope that he's learned from the club's numerous mistakes during his time here.
If someone else comes in then I won't be shedding any tears for Tan, but we could do a lot worse.