Hi Joe,
Now that all custom traffic variables can be enabled with full pathing I feel that is a strong option in most of these cases. You would only have to allocate a designated 'form' custom traffic variable and then on each request you can distinguish the form and track along as users proceed through a form on each step. You can also set up the custom traffic values in a logical manner so that you can classify and group values in your reports.
You can use events to track drop off and calculate progress rates, but as you note you might have to allocate events per flow to distinguish. Events are good because they then attribute to traffic sources/campaigns and can report out alongside your other conversion events. So if you have major form milestones that you want to bring into your reports as a metric then it may be worth it to implement events.
So I would recommend you nail down which end reports matter the most to your organization in tracking forms and how much detail you need to track. You could also do a hybrid approach where it makes sense and track with a custom traffic variable allocated for form requests and set events to allow for the metrics view.
Best,
Brian
