I've heard great things about YourKit but their web presence is amateurish.
The jProfiler site seems much more professional and informative. I can't help but wonder if that extends to the product and support as well.
The pricing, at least for single per-seat licensing, is almost identical.
I primarily develop server side applications and would really like to get a better insight into how that code is performing.
All of the reviews I have seen are pretty old and it seems both products have been heavily updated recently.
Why did you choose YourKit? Have you compared it with jProfiler?