Hussar
Legend
I'm going to go with Imaro on this one, just for the novelty of it. 
Going gridless in 4e, and 3e as well IMO, is going to put a lot of pressure on the DM to track elements. In 3e it might be a bit easier since encounters were typically fairly small. 4e defaults to much larger encounters, which makes it that much more difficult to go gridless and still retain detail.
Now, if the DM is just ignoring the fiddly bits, fine, but, that doesn't make it easy to do 4e gridless. That means that a particular homebrew which ejects the fiddly bits is easier.
Kind of like ignoring space requirements for weapons to come up with either 6 or 8 opponents surrounding the human fighter (I'd still like to see the weapon breakdown of those numbers considering a two handed sword requires 10 feet of space IIRC - it's been a LONG time and OSRIC doesn't include this rule apparently.) Or ignoring the weapon vs armor table.
Sure, it speeds things up, of course it does. It also has a pretty serious knock on effect of making longswords absolutely king - far and away better than any other weapon in the game, and also tends to help out monsters since the PC's will generally be better armored than the bad guys.
As far as empowerment goes, I'd say that the grid has to empower the players rather than the DM. Without a grid, all placement is entirely in the hands of the DM. If he wants you to do something related to location, or he thinks it's ok, then you can do it. Otherwise you can't. Having the grid forces the DM to specifically place all the actors, removing the requirement for all player movement and space related decisions being filtered by the DM.

Going gridless in 4e, and 3e as well IMO, is going to put a lot of pressure on the DM to track elements. In 3e it might be a bit easier since encounters were typically fairly small. 4e defaults to much larger encounters, which makes it that much more difficult to go gridless and still retain detail.
Now, if the DM is just ignoring the fiddly bits, fine, but, that doesn't make it easy to do 4e gridless. That means that a particular homebrew which ejects the fiddly bits is easier.
Kind of like ignoring space requirements for weapons to come up with either 6 or 8 opponents surrounding the human fighter (I'd still like to see the weapon breakdown of those numbers considering a two handed sword requires 10 feet of space IIRC - it's been a LONG time and OSRIC doesn't include this rule apparently.) Or ignoring the weapon vs armor table.
Sure, it speeds things up, of course it does. It also has a pretty serious knock on effect of making longswords absolutely king - far and away better than any other weapon in the game, and also tends to help out monsters since the PC's will generally be better armored than the bad guys.
As far as empowerment goes, I'd say that the grid has to empower the players rather than the DM. Without a grid, all placement is entirely in the hands of the DM. If he wants you to do something related to location, or he thinks it's ok, then you can do it. Otherwise you can't. Having the grid forces the DM to specifically place all the actors, removing the requirement for all player movement and space related decisions being filtered by the DM.