Yes, and the New Geneva Study Bible originally appeared in the NKJV as well. One minister in Northern Ireland made the same observation to me as you did, that the NKJV never really gained the same popularity there as it did here.
I have read the TBS booklet on the NKJV. The criticisms basically boil down to the following points:
1. The NJKV has the false appearance of being a faithful update of the Authorised Version whereas a close examination of verses shows that it is a completely new translation which deviates from some of the interpretations of the AV. At this point the booklet documents a number of them (e.g at Ephesians 4.12. There is a significant difference of whether the pastor/teacher is given for the equipping the saints, for the work of ministry--as two distinct purposes of the minister--or whether he equips the saints themselves to do the work of ministryper the NKJV.)
2. The NKJV has the critical readings in the margins which gives a kind of legitimacy to the practice of modern text-criticism.
3. The NKJV is under copyright which TBS belives to be a wrong practice.
There are other points as well, but these seem to be the major ones.
I would add that the NKJV did not receive official eccelsiastical sanction and so it serves rather to disunify than unify.