What do you like best about the product?

Webload is easy to use, you can create simple tests with a built-in recorder or you can write sophisticated scripts inluding several techologies and frameworks like Java and Selenium on top of JavaScript which is the main language. It has various reporting features which can be customized by the user regarding to their needs through UI (temporary) or (permamently) through template files.
It has competetive price and good customer support. My team is using WebLoad on daliy basis. Recommended!

What do you dislike about the product?

If you want to have a various customizations like custom reports or sophisticated scripts, you need to be experienced user in software/programming, hence in some way it reminds me open source tools, but in some way it can be an advantage, since you can do your own customizations.
Lacks of capabilities to tes reactive (async) based UI, this is the biggest disadvantage. For that purpose we use Selenium + Java + Webload, but it is not very easy to maintain and write the scripts.

What problems is the product solving and how is that benefiting you?

You can test your POC's and then propose to the corresponding teams to implement them in the product.