I'd like to share this solution (in progress) that I've come up for comparing conversions through a registration page which is split over multiple pages. It's not perfect but seems to be working as the real version of this anonymised example is helping drive the decisions it was designed for.
There are 2 conversion rates. One is Impressions to Register and the other is Step 1 to register. This is the % of people who register who have started engaging somewhere on the form by entering something. I do this because depending on the traffic source we can get a huge bounce rate which distorts the data.
The first thing to look at is the background colour. This is the step 1 conversion rate. I can immediately see that Feedme.net (fictional companies here) converts better than the rest and mainly on desktop and mobile. We seem to be having big problems on GoEat.biz
I can then switch the view to the actual form step names and filter on the people who didn't complete the form to see drop off points. I already show where the errors are generating on the page. I've left an impressions indicator in the bottom right because if you are looking at the percentage view then it's handy to see which parts of the graph have the most users behind it.
There are a few annoying bugs in it and I can't wait to get my hands on the Tableau version where we can show pop out charts to add more to it but it seems to be okay so far. Have a play and let me know what you think!