If you're in the Messenger Stand mate, ffs take a hat and sunscreen - I kid you not you will be burned alive there if you don't.
The Brewongle is a massive stand, on the western side of the ground, so you will be out of the sun, but the reflective glare will get you anyway, by way of warning.
The view there is only impeded by either the roof of the stand, which means you may not be able to see the outlfield onthe other side (thoug I think you'll be right) or, if you're at the end closest to the Ladies Stand, there might be a portion near the Paddington End sightscreen out of view. Certainly, afaik, there's no impediment to seeing the pitch or infield, which, if England is batting, is where the action will be as they won't hit it off the square.
For the Messanger Stand, wasn't aware the view was obstructed at all tbh. Certainly not of the centre of the ground. Again, I imagine if you're impeded, will be a portion of the outfiled at the other end of the ground from you.