I live outside of Boston and have been to all 30 MLB ballparks (I believe 44 total ballparks that include multi generations of Teams parks, ie. Expos/Senators I have been to Jarry, Olympic, RFK and the new one). Anyhow, I have never heard anyone say they miss the old Boston Garden. If there was a new Fenway, same thing, no one would ever say they miss the old place.
When you factor in leg room, width of seats, sight lines (if you sit near the Pesky Pole you are facing the visitor's bullpen), Obstructed view seats, ticket prices, food prices, bathrooms, and the greasy stench of cooking underneath the grandstand, Fenway is low on the list for overall comfort. And I have seen the largest rats ever in the bleachers. I'm trying not to call it a dump, but it is.
As far as ticket prices, very high. Yankee stadium is higher. Most other ball parks have plenty of lower priced tickets. Many times at other parks I buy from scalpers on the street and can usually drive the price down. A couple of years ago I spent $132 for 4 tickets on Ebay for a game at Camden Yards that included parking and were shipped overnight. The seats were 4 rows back from the far end of the visitors dugout. Those seats are 400-500 at Fenway
In my opinion, Wrigley is nicer because it is so much cleaner. Both neighborhoods are great.