It seems pretty clear that how well we think Darren is doing, depends on how good we think the squad is.
Personally, I don't think it is that good:
Johnstone, Dawson, Livermore, Rodriguez, whilst decent Championship level players are very over-rated by some.
The likes of HRK, Bartley, Mears and Brunt (in CM) are pretty universally lambasted as not good enough.
Morrison and Phillips are injury prone and inconsistent.
Harper, Field and Tosin are still learning their trade.
Which leaves only Holgate, Hegazi, Gibbs and Gayle as genuine quality.
He picks the 11 that most would pick, in the formation that most would pick, so not sure he could do much different. His in-game management is suspect at times but we don't have a wealth of riches on the bench, especially in an attacking sense.
Would a different manager have us in the top 2? It's certainly possible, but a different manager could also have us in the bottom half so, for me, he's making a decent fist of it and, hopefully, will get us over the line and we can all unite behind him.
I'm sure though, that, even if we go up, there will be those that say he got lucky, is not good enough for the Prem, and the cycle will begin again.
History says that, if you say a manager isn't good enough, sooner or later you will be proved right.