Perhaps it wasn't clear enough, but the post pointed out that typing 'bundle exec' and explicitly using --path isn't necessary. Once you've added one item to your PATH, and two lines to your bundler config file, you don't need to think about it ever again, it just works. If you want all your gems in one place, simply remove the BUNDLE_PATH line and change the BUNDLE_BIN directory to whatever you want (presumably something within your home directory).
I don't want to get in to the rbenv vs RVM debate - they're both good tools and it's an issue that has been done to death. I linked to five articles in the post, and you can find many, many more with a simple Google. My personal motivation for switching was that bundler's overridden 'cd' function includes some commands that fail, which is fine under most circumstances but it breaks as soon as you use 'set -e' in bash. We spoke to the author and he said he said that RVM wouldn't be 'set -e' compatible in the foreseeable future.
To be clear, my goal is not to sway your decision, but to provide an informed discussion for those making the evaluation. Whether we want it to be, it is an rbenv vs RVM debate, because those are the tools we're evaluating.
My observation is that rbenv users often tack on additional ad hoc solutions to arrive at the same convenience provided by RVM. The primary objection I hear to RVM is the `cd` override, which is optional.