I've had no experience with Lynda but what's underwhelming about PS? It definitely seems to lack of depth in a lot of courses but provides a good overview/refresher on things in my experience.
As you mentioned lack of depth is the larger one, but also the rate at which they add new content is not exactly great. Lastly they tend to reuse the same author's for certain subjects which creates a lack of diversity in the teaching. These last two are common to both Lynda and Pluaralsight. At $25.00 and $30.00/month this is one of the highest priced subscription services on the internet and as such you would expect much more from them.
Yeah I'll admit I hadn't considered lack of instructor diversity. Subscription fees are thankfully paid for by my employer so it's not a huge issue for me personally but I could understand how that would be difficult to justify for individuals.