There aren't too many problems with this model. If there are any adjustments I'd suggest, I think there should be more keyframes for the face aside from the expressions that are based on the images we saw on the main page. Here are some bullet points for the recommended keyframes. I'll still be ok with using the bones though.

-Eyebrows (one each)
-Lower eyelids
-Mouth (Happy, Frown, Teeth Grit, etc.)

One more critique I have for this one is that it's noticeably missing some Ambient Occlusion. I think adding it would not only make the shading look better but it would also make it look more natural. But that's just my recommendation.

Other than that, the model is great.

I agree with Travis, the facial expressions from the old one put onto this one would be awesome. (I know he has bones, but those plus flexes are always better than just one or the other. The other problem I see is when you bend his neck forward, his chest goes a bit.. wonky. Like this: https://sta.sh/01tcfrpll6gh

so what exactly is different about this model than the old one that makes it not take kindly to the bone placements? perhaps some more bones in the neck(like 2 or 3 more bones) more closely following the apparent curve of his spine would help solve this issue because for some reason all the spinal bones forward of his hindquarters dont really take kindly to rotation as the model creases and folds and generally distorts in kinda freakish manners which is weird because my little pony models dont have this problem as badly despite having a slightly similar body structure... i mean dont get me wrong it is a beautiful model it's just it needs a better bone structure and a better way of handling distortion

this model sure lacks the facial expressions that the old model had,
Its a nice model tho I'll be useing the old one because of its many facial emotions you can make which this new model lacks.
Like there is no option to make him smirk.
And if you make him grin he looks more mad then anything else.

The neck also needs some work because hen you bend it forward the skin folds up.
I'm not an expert nor an content creator for SFM models. So I cannot say much on how to fix this. Tho I am sure others here know more about bones and such.

You did a great job on the model so far and I hope updates will be made.