Well, As you can see below there is a different structure on the new wheels to the left. Each wheel weighs 550g compared to the old wheels which weigh 2600g. This is a massive improvement to the weight of the board making it easier to bring with you on a daily commute.
Not only is the weight improved but you may be wondering why the wheels came with a new hanger. Well, below you can see an up-close photo of the two hangers. On the left is the old hanger and on the right is the new one. You can see the main difference is the metal cutout at the end of the wheelbase. The old wheel has a square cutout that would be inserted into that square cutout. This was due to the special nature of the old wheels. The new wheels use regular bearings which means it does not need this square cutout anymore so it got changed to a circle to set the new wheel in the same position the old wheel was instead of slightly further out.
The wheels also add ride comfort. The old wheels would bottom out on large cracks between pavement. This is no longer an issue as the increased rubber on our new wheels absorbs the impact.