The #1 reason I use and love Gunner Training so much is it's pretty much all there. Better still, it's like paying someone to sit down and plan out my study schedule as well as give me the material. There's definitely room for improvement, I think their neuro could use some work and the spacing algorithm is kind of stupid. But it's gotten a lot better with time.
I would kill for them to put in some keyboard commands, all the clicking is killing my wrist. There should be a control panel for manipulating questions and the algorithm, including a mechanism for showing your projected test date and moving questions sooner accordingly.
Hands down it's the single best resource and it's pretty cheap. The only problem is it takes so much time. Realistically, about a year depending on the person.
I also regret covering biochemistry early. Some of those questions are just so pointless and low yield. Other than that I think they did a really good job. This type of active, spaced learning based off of current research is where medical education should be rather than crap like FA, BRS, Kaplan and pirated videos.