I have never seen King Lear, so it was all new to me when we attended MTC's production of Queen Lear. It might have been better if I had glanced at the Wikipedia summary beforehand, although I am not sure. Yes, Shakespearean dialogue is not always easy to follow, and there are many twists and turns in Lear, but I don't think my ignorance of the story was the only reason that I struggled with this performance.
In fact, I read on one website - which was otherwise generally favourably inclined - that "While it is difficult at times to tune the ear to all of Nevin’s speech......" (see http://simonparrismaninchair.wordpress.com/2012/07/13/queen-lear-review/).
At least one reviewer is not kind to this production, see
http://www.theaustralian.com.au/arts/stage/queen-lear-cheerless-dark-and-deadly/story-fn9d344c-1226424964382 (sorry about the paywall, but even the bit that is accessible gives the idea!)
However, there is still much to appreciate. Nevin's performance is certainly powerful, and the rest of the cast are pretty good, too. The set during the storm scenes is dramatic, although I wondered at times whether there needed to be such a large expanse of stage during some of the other scenes.
The production is at the MTC Theatre, which looks pretty good at night!