The reason a backlit keyboard is useful is when you are in a dim environment. I can touch-type so I don't need to see the keys. I do not, however, have every single macro key perfectly memorized for every single game that I play. Due to shifting the keyboard to my left backlit keys are useful when I reach down and hit the wrong key or I'm just unsure. I quickly glance down, re-orient my hands, and I'm set.
I think it would be a great idea if Logitech sold an ergonomic keyboard along Microsoft's design but also include backlit keys, an LCD, and the general G series functionality. It would be an extremely nice board.
I do miss the use of the ergonomic keyboard a lot and I went through the similar experience of going to use someone else's computer and simply being pained at typing on a normal keyboard. The MS ergonomic keyboards have the key spacing so much more open than a standard keyboard so using a regular board can seem cramped.
It can take some time but re-adjusting to a regular keyboard can be done fairly quickly. The downside is that if you actually used an ergonomic keyboard to alleviate problems such as carpal tunnel syndrome, thoracic outlet syndrome, or tendinitis then you are going to likely re-aggravate the medical condition if you do a lot of typing. You have to make a decision to stay with an ergonomic keyboard with less functionality or go with a board with more functionality that is easier on the hands, wrists, etc. In my case I have relearned how to position using a normal keyboard so that my problem (thoracic outlet syndrome) isn't as aggravated as it could be and I make full use of the wrist rest and hold my hands in as relaxed a manner as possible both when actively typing and not. The less movement and force needed to press the keys the better.