I swapped the mag for the spoked rear wheel, but I'll also be doing the same for the fronts.
Here's a closer look at the rear drive wheel. Before and after pics. The stock mag one on the right definitely looks more aggressive but it won't accommodate the new IGH (internal gear hub).
Though uglier, the spoked one is stronger and can hold a higher tire pressure. This one's at 60PSI which is far below the limit of the wheel, but just under the 7oPSI limit of the tire. The mag wheel is topped at only 40PSI. Any damage or weakness of the mag wheel is not shown until it completely fails. The spoked wheel however will give warning signs as it starts to weaken. Spokes will come undone providing time to replace it. The mag wheel will just snap without warning. Scary.
The cassettes/freewheels are also different. An 8-sp 13-30 (13-15-17-19-21-23-26-30) cassette replaces the 11-34 freewheel. I can only use 7 of the 8 cogs on the 8-speed, so the usable cogs are actually 15-30.
Though it's not much to look at, the new spoked wheel fits on the frame's fork much better. It's super snug and doesn't wobble side to side like the old stock mags did. Feels much more secure. The quality makes for more confidence at high speeds.
Though the tires are now inflated to 60 psi compared to the old max of 40 psi, I think the extra drag inefficiency from the new rear hub evens it all out. I can't really feel the difference, better or worse.