Leave it.
If you aren't happy, replace it with something more expensive that has lots of better reviews. If your temp monitoring software reports a noticeable difference, you're sorted. If it doesn't, you've wasted time and money. Google for TIMs and you'll find a lot of "opinions" about the variations. Read them, understand them, disregard them or follow them if you want. I've used top end, mid-range and el cheapo TIM. The biggest difference was the top end (that I tried) was the hardest to use!
Try what you have and if your temps are "too high", look for other solutions. Replacement of stock TIM is likely to provide the least benefit.
T42