The enhancing part is just convenience; it's the enfeebling duration and potency that should be the real reason to get the +2 version.
Duration (in general) is more than "just" convenience to me, when you have to keep Haste2 (and more) on a whole alliance.
It's not the main selling point of the neck, but it was ONE of the selling points for me.
Without that I don't think I want to spend 150m on the RDM neck, but to each his own of course, I wasn't judging people who do, just manifesting my personal intent.
Now make that 50m and we're talking! xD
Not sure what to do now. Getting +1 while waiting for +2 price to go down?
Cons: Those are 15 mils gil that you are permanently wasting on the +1 that could've gone on the +2 fund.
Pros: It's a pretty damn good compromise while waiting for +2 price to go down, which will take quite a while.