I think you're being a bit harsh Glen. Reading between the lines of his question, I think he's unsure what factors he should be considering to be able to make the decision so some guidance for how he should approach his investment decision is not unreasonable.
Yeah, I know my position is controversial, and can sometimes sound harsh. You're right, iqi. By coincidence of timing (I've been working on it for days now), I'll be posting Part 2 of a series on nearfield monitors on the IRN website later today or tomorrow (depending on when the burgers need to be cooked

) that I believe explains the point a bit better.
There are not many, if any, brand name loudspeakers marketed as "studio monitors" that are actually poorly designed or constructed, IMHO. Some are built better than others, sure, but there's no reason why - as long as they are not abused - any of these models should not be working to spec five years from now.
Maybe that answers his question more directly...or at least the first half of it.
Other than price, there are only two real difference between monitors: 1) how they sound, and 2) who's listening to them. Those two factors are inexorably linked. No one can tell someone else that one monitor sounds "better" than another, because everybody has a different definition of "better". And those definitions are not necessarily always directly related to measurable quantitative terms such as "flatness" or "accuracy".
This means that the only person that can, IMHO, answer the second half of ESP's question is ESP.
I know that is most definitely not the answer that everybody wants to hear, but I don't see how it can possibly fall out any other way. For anybody to say that Model A will work better than Model B for someone else - or vice versa - has at best a 50% chance of being right; this is the equivalent of saying they will be giving a wrong answer half the time.
If that sounds harsh, then reality is harsh in this instance, and I'm not sure how to make it otherwise.
Additionally, while I agree with the general concepts you lay out about the woofer size and crossover, which one will actually be better suited for ESP (or any other one person) will depend much on his actual room configuration. For example, if he's limited by circumstance to a smaller room where he is forced to have his monitors closer to the back walls or corners than we would normally recommend, he may actually get a more translatable response out of the smaller speaker.
For another example, in this specific instance of the mAudio BX series, even with the 8", it only goes down to 50Hz @
-10dB, and at real specs of ± 3dB or less, only about 60Hz. It could be argued that both the 8 and the 5, a subwoofer would be warranted for the real bass. And in fact, the mAudio subwoofer is speced to match these weakness rather well.
G.