The new entrance is nice, until you walk in and are greeted by the exact same old configuration with massive lineups prior to game time. I'd be surprised if anyone on here ever enters through the main entrance. Entering on the side door has always been a better option and even more so now.
I actually like the new entrance - I used it every time coming out of the T in December, before the underground tunnel opened. Every time I walked up the side doors with huge staircases, there was only one person there to scan everyone, and I always saw a huge line outside - then again, I'm thinking back probably two years ago, which was the last time I used it. Plus, I can get my steps in inside the Garden going from level 4 to level 7 - I don't mind taking an escalator up to 2.
I've never found the main entrance by the ProShop to be particularly backed up. Then again, I'm often going up about 35 minutes before the listed game start - I like watching practice. But I swear sometimes I've arrived 5-10 minutes before game time, and it's been fairly smooth. The only time I see it backed up is when they first open the gates on a giveaway day - the Running of the Bobbleheads can be almost as dangerous as Pamplona. (Seriously, I get that they want to trap people inside for food/beverage purposes, but the damn sponsors need to supply more than 5000 of an item.)
Parking for $50 is nuts. I'll never park at the Garden - if the T is undergoing their green line disruptions, I'll do my own little odd parking job - $15 by the Boston Opera House, close to the Chinatown stop. I'm sure there's a closer and faster way to get it, but it works for me.