I noticed you've got a fill/drain tube attached to the top of the res.... if that wasn't in place, would you have enough room to drop the res forward to fill it?
Quick answer is yes, but I wouldn't want to fill a res over a motherboard! :haha:
I have the fill tube routed behind the back of the case and fill it from the other side.... this is something that just kind of happened when I set this loop up with the new res. Thankfully I had a 45 degree elbow that just -barely- skimmed the top of the case/rad to route out the back. This is also the reason I cannot do a push/pull on the rad - I can't lower the radiator any more.
For draining, I can just pull the reservoir down, and use it as a drain tube - the only thing holding it on is the two clips, from the tubes connecting the video card, to the rad. The whole thing just pivots forward to drain.