Since going down 23-19 at home to Glasgow on September 17 the reigning Heineken Cup champions have swept all before them, culminating in the defeat of Cardiff last weekend.
The victory took Leinster nine points clear of nearest challengers Ospreys and ten points clear of great rivals and defending champions Munster.
However Sexton, who is likely to be named in Ireland's Six Nations squad next week, claims coach Joe Schmidt is far from satisfied.
"There's definitely room for improvement. Even though we've been getting the results at times aspects of our performance haven't been great," he said.
"The good thing about Joe is that even though we are winning he is highlighting flaws in our game and things that we need to improve on.
"That is great because it keeps us improving and if we can keep getting better and better and not just getting the results but also have the performances to go with them then we'll be in a good place."
Sexton has appeared four times for Leinster in the RaboDirect PRO12 this season, including an hour against the Blues in Cardiff which saw him contribute ten points.
And with the Six Nations on the horizon, Sexton admits he's keen to get back into his rhythm sooner rather than later.
"It is difficult at times, I felt like I was coming into a really good bit of form with the two Bath games [in the Heineken Cup] and then we've got an enforced break for a couple of weeks and it really feels like you're starting the season all over again at times," he said.
"Hopefully the 60 minutes against Cardiff last week will get me back playing well again in the Heineken Cup games."