In terms of bag complexity, I really don't feel the Overlander30 is significantly more complex nor significantly more time consuming to use. It might seem initially to have a lot going on, but in practice (at least for me) after the first couple times using the system it was quick and easy. Don't for get that a lot of the strap options, strap length and strap adjustments are designed to make the bags useful on a varity of machines by all sorts of people with differing ideas of the "perfect" fitment. Once you have played with the bags a bit and have them right where you want them, you won't have to fiddle so much and you have the option of trimming straps if they are in the way.
You mentioned that with the Coyote you are able to access your tools from the lower parts of the bag by working the zippers around. I agree that the Coyote gives you that ability, but at the cost of having gear higher up on the bike. To use the full 30L that the Coyote has to offer you have a bunch of gear on or above seat level, the Overlander30 carries almost all of it's 30L bellow seat level. A benefit IMO. But yes, access is only from the top of the bag so things may need to come out. In many of your photos it looked like the opper portion of the Coyote was just not used, maybe to keep the seat clear? If so, I think you will find the Overlander30 allows you to carry more.
I also had DirtBagz... just erase the comparrison from your head. Both the DirtBagz and the Overlander30 are black, there is one bag on each side of the bike. That is the extent of the similarities.
To me, the only negative (for you) to the Overlander30 is the buckle that goes over the seat. It was mentioned that it could be removed and replaced with a velcro strap and while that is certainly an option; I have found the cam buckle in the seat strap to be an integral part of the Overlander30s mounting system. Once all the over straps are tight and the bags are packed I have found cranking the over the seat cam backle tight is what really keeps the system from moving around. I don't know what your options are... I tried the cam buckle under the seat and it didn't really work. As mentioned, you might be able to shorten the strap on the cam buckle leash to move it more to the side of the seat. You might be able to remount and thus move where the cam buckle seat straps mount on each of the bags.
As I type this I also think it is worth mention: As I stated above, the seat strap cam buckle gets cranked tight (at least that is how it works best for me) as the final part of making the bags secure. When the seat strap is pulled tight, the top corners of each bag are pulled together and squeeze in on the seat. Depending on where you sit, and how fat your ass is, I could see this also being a "problem". For me, if I am on the rear portion f the seat I notice the bags but they are not a problem. I had much more of an issue with the upper part of the Coyote interfering with my backpack during technical riding.
Just my 2 cents.