Gotta luv the G-Nug! The Golden Nugget is hands-down the nicest hotel in the downtown area. I prefer downtown when I'm in the mood for a gambling/drinking trip to Vegas vs. an upscale shopping/clubbing trip - for that - you go to the strip.
The check-in process was slow but after that service was not an issue. I did not stay in the upgraded tower but my friends did, the only difference between regular rooms and upgraded rooms is the decor, the rooms are the same size. Personally, I wouldn't spend the money for the upgraded room. In our case (Superbowl weekend) there was a $100 per night difference.
We pre-booked our rooms using a travel website and when we checked in they informed us that the price per night had dropped and we were issued a refund, pretty cool, right? Score.
The casino is pricey but they do have a really fun and really cheap virtual poker/ black jack game - try it! The Rush Lounge is also fun for a cocktail and the Grotto makes a dynamite lasagna!
Like I said ... Gotta Luv The G-Nug!