We have been using Trevor in our Marketing team for over a year and are extremely happy with the product!
The speed of improvements made by these guys never ceases to amaze me.
If you fall into the majority category of people who want to access and manipulate key data stored and don't know SQL, don't rush to learn it, just use Trevor.
Super attentive to feedback, detail and requests for help figuring out how to query something a little bit "out there" (by non-Techie standards) - as far as I'm concerned, it's a product and service unrivalled for what it's made to do.