It depends on how much time you want to spend in and around the hub. You can still get the classic photo of your family from Main Street USA, looking toward the castle, with no sign of the construction walls. (We were in WDW last week, and the only time we saw the construction site itself was in looking back toward the moat from various locations in Tomorrowland.)
The only real issues the walls presented for us related to traffic problems and fireworks viewing. As it happened, we had no view of the castle at all during Wishes because we ended up on the "wrong side" of the construction walls -- we could still see the fireworks above just fine -- but that could have been corrected if we'd showed up more than 30 minutes prior to Wishes and staked out a place further down Main Street or closer to the castle. By 9:30pm on an average crowd day, however, everyplace you could stand and not have your view partially blocked by a construction wall was wall-to-wall people. If you don't mind not seeing the castle though, the construction wall area is actually a great place to stand, since very few people want to have their view compromised, so you'll have plenty of elbow room and an easy "escape" after Wishes is over.
And again, the walls do create "traffic" snarls in the hub area, particularly around parade and showtimes, by thinning the walkways and making it confusing for people who don't know the hub layout, and aren't sure precisely where they're going because they can't see through/around/over the walls. After our first visit to the Magic Kingdom, we did our best to avoid the hub altogether, and started taking the WDW Railroad from Main Street to our desired destination instead.
Also, in making our photo books of the trip, I "cheated" and used stock/free photos of the pre-construction hub and castle from online. The construction walls are one "memory" we don't really need to retain.
If they really bother you, that's always an option.
