Microsoft's Surface Book 2 was announced in November 2017, so when it was refreshed in May, it was a welcome change. But if you were expecting a visual change, such as a smaller hinge gap, that's not what the Surface Book 3 is all about. In fact, the chassis is exactly the same as the Surface Book 2.
This year's model is all about more power. Microsoft went with Intel's 10th-generation 'Ice Lake' processors, rather than Comet Lake. This is an interesting choice. While Ice Lake is 10nm, the CPU isn't as powerful as 14nm Comet Lake. Ice Lake makes up for it by using more powerful Iris Plus Graphics, but that's not as important in a machine with a dedicated GPU like the Surface Book. It does, however, mean that you'll get a lot more graphics power when the display is detached from the base.
The GPU got an upgrade too, as it now comes with an Nvidia GeForce GTX 1650 in the 13.5-inch model. Unfortunately, it's still a GDDR5 variant of the GTX 1650, rather than the newer GDDR6 that's in the GTX 1660 Ti that's in the 15-inch. Other improvements include configurations with up to 32GB of RAM, and the ports have been upgraded. The two USB Type-A, one USB Type-C, and Surface Connect ports are all now USB 3.1 Gen 2, so they'll get 10Gbps data transfer speeds instead of 5Gbps.
The model that Microsoft sent me is the 13.5-inch version with a Core i7-1065G7, 32GB RAM, and a 512GB SSD. As with all of the Core i7 models, it includes the dedicated GPU, which in this case is the GTX 1650 with 4GB GDDR5.