Personally, I think it could be better if they brought refuelling back but made it optional rather than mandatory... Would possibly throw up a lot more options in terms of strategy that could see some interesting results.
Of course some tracks it would be a no brainer, but think about a track like monaco where someone might rather try to take the advantage of quicker pitstops for track position rather than a quicker car, but longer stops and then being forced to overtake...
In fact, do the same with tyres and do away with the stupid mandatory use of each compound, just make it that the drivers can use whatever they want, whenever they want!
The possibility between trying to make it round without a single pit stop (and to the nay-sayers, many drivers DID do that in the 80's when it was possible, so there's no reason tyres can't be developed to do this!), versus someone in a quicker car, stopping for both tyres and fuel twice in a race, losing close to a minute in track time though may be 5 seconds a lap quicker!
I think we'd see a lot more surprise results, different teams winning, mixed teams in the points and a whole lot more overtaking and incidents than we do at present...
So there we go - my opinion, different tyre compounds and refuelling, but all of it opional allowing for much more, and more diverse strategies! Less predictable and more exciting!

Favourite racing series: F1, Indycar, NASCAR, GP2, F3, Formula E, Trophee Andros, DTM, WTCC, BTCC, World Endurance... etc. etc.