First off, I love the title of this thread. I am mesomorphic as well with some strong endomorph thrown in the mix. I believe I have found the answer to my metabolic challenges, and that is eat low carb!
Seriously, I just posted a somewhat long response on the "Anthony Colpo vs Michael Eades" thread (LC Media I think it is), talking about my experiences just these last 3 months with the LC way of eating.
Congratulations on your progress to date. Those are some nice numbers I am seeing, particularly the loss of bodyfat. It always makes a more dramatic difference in one's appearance than just the attaining of additional muscle. As a man I can certainly vouch for that.
You know, I am not likely to ever start a gym log myself as I have no time or even inclination to hit a gym anymore. I just do my pushups/chinups/pullups/dips in the privacy of my home. I make them as difficult as possible and rest assured when you are lifting 220+ pounds as I am, it is some workout.
BTW, I hate cardio as well, just not built to be a cardio guy (love swimming for obvious reasons, no pounding of joints), but you should consider Tabata Intervals (Google it, no shortage of what you will find on these amazing protocol). Run it by your trainer to see how open minded he or she is. I have been performing it with a skip rope. Good luck with everything, you're doing great.
Oh, and of course, thank God for Josh Beckett!