The Baseline functionality is documented (and demonstrated) as capturing both timeline and financial data. However, it doesn't actually work. When a project's financial information (budget, planned revenue, etc) change, it changes in all the baselines.
The financial information is probably the most important data point to have as a way of tracking a project's performance and trajectory over time (for us, anyway).
The support team, our implementation team, and the developers said this the way it works now, although they all agree it "doesn't actually make sense." They suggested using the power of the community to speed up the fix; otherwise it will be whenever they get around to it.
CAN YOU UPVOTE BASELINE FUNCTIONALITY TO ACTUALLY CAPTURE FINANCIAL DATA AS DOCUMENTED?
From the Experience site: "A baseline takes a snapshot of the name, dates, and financial information. The baseline does not include the values of custom fields on the original project."