I've read all of the 'Shatnerverse' novels with the exception of Captain's Glory. I thought the first two trilogies were awesome- they are actually what got me into TrekLit in the first place. I wasn't as enamored with the third trilogy and am not exactly chomping at the bit to read book number 9- possibly because, having discovered the wider world of Trek Lit, my standards have altered.
I think the minor continuity variations mentioned by Christopher, while valid, don't really cause a problem for me. I don't sit there with a Calendar while I read TrekLit, and unless there is a really obvious continuity hole then I am happy to shift events around in my mind to make the continuity fit. The annoying thing about the Shatnerverse trilogy is that people called it the Shatnerverse long before it conflicted with the TTN series, primarily because massive, epic events occured in the Shatnerverse (a Federation-wide plague, for example) that weren't really registered as having occurred in the DS9 relaunch continuity. I didn't really see a problem with this and I think it was just snobs who thought the Shatnerverse didn't live up to their idea of what Trek was meant to be, deciding to put it in it's own continuity. As far as I am concerned both continuities coexist with each other in my mental space. That's just me, however, and I respect that, because the Shatnerverse does play fast and loose with epic events in the Trek continuity, that the relaunch continuity made the right decision in disregarding them as 'real' events, to be referenced.