Just come back from the Mull after 4 days there, which I do every year. Just thought I'd add my thoughts on the matter, and my mate who's lived in Sandhead all his life and knows the place like the back of his hand.
The problem with the mull is any decent wind with west in it, prevents you fishing all the Pollack marks on the West coast, and there are countless that still produce excellent fishing. When this happens (and its just happened to me for 4 days), you're not spoilt for choice anymore. If you want Pollack, you have to go down the end of the mull. Trouble is, everyone has the same idea, and as its a relatively small area, its gets packed...and overfished.
Another option is Bass. My mate has told me its been poor this year, and it was terrible when I was there (1 lost fish in over 12 rod hours). This was before all the rain that the remnants of the hurricane dumped over there last sunday. As a result, all fresh water streams running into the bay were in spate. The water where I fished was nowhere clear as it usually is. There were also Smoothies being caught around a couple of the bays. I fished one night tide for them , but all I got was dogs.
I'm also told that the illegal razorfish collection isn't helping things either, as it may just stun the razorfish, but it kills all the fish fry etc in the area.
One more thing about the marks on the West Coast. The seal population is a real problem over that side now.
I don't think the Mull is anywhere near fished out, but be prepared to have other plans in place as your options are severely limited if you can't get to the west side.
I'll still be back next year though