The NKJV is my favorite modern translation as well.
With regard to quality editions, there is supposed to be an Allan edition in the works, but it's supposed to be based on a Holman text block that has maybe 8 pt. print. If it has red letters there's no way I'm going to shell out that kind of $$ for one. The only "black letter" NKJV's I can think of are the MacArthur Study Bible, the NKJV Study Bible and the
recently published single column edition. There is a Cambridge Pitt Minion NKJV edition but it has red letters, as most Cambridge editions do these days. I see there is a Cambridge Wide Margin edition too. The Thompson Chain Reference should be better quality than Nelson but I've seen people complain that Kirkbride's construction isn't what it used to be either.
Nelson's construction used to be a lot better but at some point over the past 15 years or so they figured out the people will still buy even if the quality is low. (Perhaps that's a reflection of people buying Bibles that don't get used much except on Sundays.) I've seen NKJV's from the early 90's that were Smyth sewn. That even includes a hardcover Study Bible that I have that is copyright 1991. Now you can't find a leather bound Nelson Bible in any translation that is sewn, with the exception maybe of commemorative KJV editions from 2011. My NKJV MacArthur that I bought in 1999 is sewn and has a high quality genuine leather binding. By contrast, my wife's that was purchased about 3 years ago is much more worn out, and it's not from more use. I do have a glued NKJV edition that I bought around 2002 that hasn't started falling apart yet. Maybe it just has more glue than some others! I notice the spine is more flexible (without breaking) than some other glued editions from various publishers, so that is probably a big help.
I haven't kept up with it lately, but the
most recent CBA list of bestsellers still has the NKJV outselling the ESV. I've never seen the ESV outsell the NKJV on that list. But ominously the NLT is #2 in unit sales! But I don't know if that the usual breakdown now or if it's just a one month anomaly. When I would check it a year or two ago, typically it would be NIV, KJV, NKJV, NLT and maybe ESV at number 5. But the NLT is a big seller regardless.
Maybe the NKJV isn't used much in Presbyterian and Reformed churches. That was my experience when I was in those circles (PCA, OPC and EPC.) I don't recall ever seeing anyone preach from it as opposed to the NASB, NIV and ESV. Even there, the NKJV New Geneva/Reformation Study Bible never caught on the way the ESV one has.
A lot of Baptists use the NKJV. But overall, I won't be surprised to see the ESV start outselling the NKJV in the next few years. The younger Baptists I know predominately use the ESV. While there are certainly exceptions, typically the men who preach from the NKJV are older, maybe 40+ if not 50+ on average. I know at least one preacher who has switched from the KJV straight to the ESV without stopping in between with the NKJV. A lot of preachers still use the NASB too, but that's probably mostly men who cut their teeth on that version.
Crossway seems to have figured out that people prefer quality. That's something they have now over Nelson and Zondervan. (Holman is better than those two, with most editions being sewn albeit almost all in red letter.) When the ESV was first released in 2001 their construction was no better than Nelson's and was worse in some cases. The first ESV I had started falling apart after a year or two and it wasn't really my go to Bible. Now even the ESV Value Thinline has a sewn binding, although it has no ribbon marker. (Does omitting the ribbon really save that much $$ for them?) More of their editions have "black letter" too. They've also been receptive to input in that regard.
While it's certainly no literary masterpiece, I don't think the NASB is as bad as some assert unless the person is has difficulty reading in general. (But that's in the eye of the beholder as well.) The 1995 version reads smoother than the 1977. I find that in most cases it doesn't read that poorly until you compare it to another version. It reads better than it sounds. That being said, the vocabulary of the NASB is sometimes more modern than the NKJV and occasionally moreso than the ESV, which sometimes favors what some would consider to be somewhat archaic poetic expressions over more modern phraseology. It's the sentence structure of the NASB that is more awkward. And I've never really been able to stomach its translation of the Psalms compared to other versions. But that's due more to aesthetics than inaccessibility.
All of the formal equivalent editions are going to look relatively inaccessible next to the NIV, HCSB or NLT. One reason that I abandoned the NAS in favor of the NKJV was continually seeing footnotes in the NASB that said
Lit. xyz and seeing that rendering in the text of the NKJV, with the NKJV usually being more memorable as well. This seemed to be more pronounced in the OT but can also be seen in the NT with the NKJV literally translating Hebrew expressions like "gird up the loins of your mind" whereas the NASB will have something more modern and accessible like "prepare your minds for action."
Even though I prefer the Byzantine text, for some reason when reading the NASB I've tended to have more "Aha" moments than with any other version. (It seems to happen most often in the Epistles.) Maybe that's because I don't read it as much anymore or because the language is less familiar to me (albeit more modern in some cases) than the NKJV or KJV.
Someone had linked to Michael Marlowe's site. The NKJV review there is a revision of his original article. His original one was rather negative because he favors the critical text. But obviously he's reevaluated and recognizes the merits of the NKJV now, textual issues aside. The ESV article is actually a little more negative now than it was initially.
Okay, that being said, after the NASB, the NKJV is my favorite translation. I prefer the textual basis of the NKJV. I use the NASB, but do my own translations from the TR and the Byz. If they differ, I use the TR or Byz. reading. 
