Mixed thoughts about your new neighbors??
That section of the strip has been barren for 15+ years. There will soon be a big boost in people traffic right where you will be. Could be worse... you could be stuck somewhere on Tropicana in an old auto parts store that 90 - 99% of Vegas tourists never see.
While the new building will block the view of yours from the sign they'll see it as they head back north into town. Going to see that sign is probably the most popular thing people do after they get settled in to their rooms. Given the choice of tourists seeing you while heading into town or on their way out of town, I'd choose the first.
I'd be more concerned about having a plan to maintain, and preserve all of the machines with all the increased usage they'll soon be seeing (and of course building and getting it open).
I see it all as a HUGE gain, and can not wait to see it open!
-Paul