i prefer ubuntu(easy) than RHEL.
i am not blindly supporting. i had my past experience.
we used RHEL 5/6 series.
we are web developers with ROR,postgresql,hadoop,golang(REST-API),angular2-dart,selenium,etc.
we were using puppet(server-agent) , chef(master-node-workstation) to replicate the infrastructure,
we used rvm/rbenv to install ruby VM.
but we have some issues with yum/rpm with RHEL.
for examples if we want to install latest rubies like 2.3.0 , it is little complex in RHEL.
because few c/c++ libraries will give dependencies issues like libyaml-x86-64,libyaml-i386,etc.
similarly we have many issues while updating packages to latest.
installing/uninstalling in RHEL is little headache .
we have more than 40 servers so we have to use puppet/chef.
there are many opensource puppet modules and chef cookbooks for ubuntu than RHEL.
recently we are migrated to ubuntu-14.04, which seems more stable release than the earlier.
it is very easy for us to code install/uninstall instruction for puppet/chef/Dockerfile,etc.
because apt source code repositories contains latest libraries.
apt package manager resolve many dependencies by itself, handling mismatch versions. with apt you can easily uninstall/remove pkgs.
apt repositories has latest source code for many of the open source technologies like ruby,rails,postgresql,golang, selenium,angular2-dart etc
recently we are moving to micro services, kubernetes,docker swarm, where we must have to use containers .we have to write many Dockerfile/s.
ubuntu is very suitable to work with Dockerfile/s docker containers, etc.
here again i prefer ubuntu than RHEL.