Hi Alexis Shamsi Hughes - in 2014 the company I was at evaluated Pardot and Marketo as we migrated off of Eloqua. At that time, Marketo had Pardot beat hands-down in nurturing and personalization capabilities. However, the marketing team was not very sophisticated and we frankly didn't need much of the superior Marketo functionality. Pardot's price was significantly better, as we were packaging it with a Salesforce purchase at the same time. Marketo had my vote, but we went with Pardot. Ironically, the Pardot/SFDC sync was a constant source of problems. Pardot's usability was good - end-user training was quick and successful. Quicker than Marketo training, much Marketo training is longer because it is so much more powerful. I've heard that Pardot has greatly improved their nurturing capabilities - if that's true, it could be viable alternative to Marketo for a marketing team of medium-level sophistication.
I know you also asked about support - from my experience managing both platforms I'd say Pardot is on-par (PUN!) with Marketo.
Let me know if you have any other questions.
You'll probably get comments similar to what David said from the community. When I first started at my current job (2013) we were using Pardot and in the process of switching to Marketo. My take on the tool mirrored what David said... Pardot was not as robust and lacked a lot of functionality that Marketo had at the time. Not sure how much Pardot has improved through the years, but agree it is probably easier to learn how to use Pardot when compared to Marketo (like driving a car as opposed to flying a helicopter or airplane).
That being said, what is the primary reason that you are considering making the switch? Cost? Integration? Interested in your thoughts.