As a relative newcomer to AWS networking being thrown in at the deep end, this gave me a really quick and easy to digest view of what the pros/cons of various connectivity options are and what the potential pitfalls are of each approach. Very useful presentation, will be saving this for future reference.
Fast forward to 2022, few updates before my CSA Pro exam. 1. Direct Connect Gateway (DXGW) can do E-W routing too if the On-prem advertises supernet CIDR block to the DXGW. 2. TGW Peering - both Inter-Region and Intra-Region peering are allowed.