If "losing its character" means more bogs and showers, a better layout, a smarter look to the whole place, a restaurant (lord, with tables and chairs too), less human traffic jams, more pit garages (so more entries) then hurrah for that. OK, the concrete and glass is not my choice of architecture. At the end of the day, teams financing entries these days is about sponsorship, and sponsors expect market exposure and somewhere nice to go - without half decent facilities, the sponsors stay away, and you don't have a race with a half decent field.
Some spectating areas (i.e. bits where you could squeeze round the back of a building have disappeared), but the area now inside the track running from the pedestrian tunnel up to the Dunlop chicane is good. And no, the view from inside the Esses it is not as evocative as the old straight run down from the Dunlop bridge, but that has gone forever - but what you can see now from the new banking is a full view of the track all the way from the Dunlop bridge, through the Essses to Tetre Rouge. Nice.
MG Mark