Derbyshire head coach Karl Krikken is delighted with his side's form after seeing them maintain their chances of earning a CB40 semi-final place.
Falcons eased to a 31-run win over Kent on Sunday to go third in their group.
Although only top spot will guarantee progress into the final four, they may still finish as the best runner-up from the three groups and go through.
"We played very well and have been playing decent cricket for a couple of months," Krikken told BBC Radio Derby.
He added: "We are quite new to it again (40-over game), having been away for it for six weeks, so it took some getting used to.
"But 249 was a decent total and we did pretty well with the bowling too.
"There is quite a good feel about the place at present. The lads are all playing very well at the same time - it's not just one contributing - it's everybody."
Derbyshire now have have nine points and victory over Middlessex (10 points) at Lord's on Thursday would see them leapfrog their opponents and go second.
But Sussex (also 10 points) currently top the group and have played one game less than Krikken's side so are still favourites to go through automatically.