Not sure about that. Can't recall his name, but a famous French ace that flew the Yak-3 said it had excellent all around visibility.
ack-ack
I'm not saying it'll be horrible like a F6F, just less of it. As you can see, it's a shorter canopy with the top of the rear fuselage also meeting a good few inches higher. I'm not sure about the space inside available to move your head around either, both seem adequate and near identicle, although the Yak-3's might be a hair more confined if you look at it from a forward, rear or top profile in some images.
For AH, it's probabley too little a difference to matter, really.