What do you like best?
RHEL is just the same open-source Linux you can get from everybody else, but it comes with support. That's very important for companies running mission critical systems that need someone to talk to whenever a problem arises, and they will do their best to find a solution as soon as possible.
RHEL also ensures that the software it bundles is tested and supported, so everything is usually working as you would expect. Their long term support usually lasts more than 10 years, so you really don't have to rush upgrading to the next version, and you'll have plenty of time to plan for the updates.
What do you dislike?
Having used Debian, or Debian-based distributions like Ubuntu for the most time, I sometimes find RHEL not so confortable when compared to these other Linux distributions. Things like the package manager (dnf), location of configuration files, or internal system utilities are, in my opinion, more cumbersome than the Debian counterpart.
Recommendations to others considering the product
Since 2016, there exists a "no-cost" licensed RHEL version. It comes with no support, of course, and you can't use it for commercial purposes, but at least it is a way for you to evaluate the product and decide if it fits your needs before paying for it. If paid support is not that important for you, be aware that some open-source, free of charge, derivative distributions, also exist.
What business problems are you solving with the product? What benefits have you realized?
We use RHEL in some of our servers, where we host our customers' applications. We need a stable, supported environment, where fault-tolerance and high-availability are a must.
Between all the big commercial Linux vendors (SLES, Oracle, etc) we chose RedHat because it was, for us, the most popular one and also it was offered by one of our clould providers.
We don't use RHEL in our workstations, though.