Interesting. I just started Thm and I don't know if it says it off to the left but I'm currently only rank 23. From the minimal experience I can say I looked at both sides of how the class is set up. At first I despised it because of my FFXI bias (naturally). However, both thinking and playing more brought on a few moments of me surrendering said bias.
For instance, when I unlocked thundara I wasn't psyched that it doubled as a big(ger) damage spell stacked with stun (I know most abilities have some debuff attached). As most know, if you don't combo, the damage (seems) less and the recast doubles (right?) but it stuns the target. However if I combo it the damage is bigger and the recast is only 15 seconds (I believe ha!) and stun is lost.
At first, as much I preferably would like to have a separate stun spell, I've come to enjoy the thought process I have to put into carefully choosing when and how to use a certain spell. In FFXI the challenge more or less hinged on reflex and memory of remembering which macro was for what, and how fast I could smash them all. In this game the challenge seems to be more based on good decision making.
Also, it was already said that drain and aspir come in an ability form instead of spell form, which is neat. Why is this neat? Ex: Thunder > Necrogenesis > Parsimony > Thundara. I get the big(ger) combo damage coupled with the gains from both abilities which extremely useful. Instead of barreling through multiple spell macros, I get a bigger overall gain out of just one. Cutting out the bullshit.
Finally, of course I don't know much about black mage itself, but I'v already noticed the restraints put on by having archer and pugilist as the "sub classes". Personally I would rather keep THM and stack CNJ skills to serve as a safety net in group play if the WHM were to gone down (but that's just me). I CAN do that, but I miss out all the advanced skills BLM can acquire. And I don't much care for how PGL and Archer have main stats of INT and PIE, because it's not like I get to choose my "sub classes". Maybe this was intended to ward off the "You much have CNJ sub class or no party" stereotyping that was prevalent in FFXI, but to me, what's the difference between having a choice which some may frown upon or having no choice in the matter and being simply stuck with what you're stuck with. Personally I don't see a difference.
Aaaaaaaand we all know everything is pretty much getting redone, making this pointless. If anything I'm just trying to put forth some examples to the OP of what I personally have noticed about how the THM class differed from ffxi blm (without putting any positives on FFXI blm, sorry, but they were already mentioned, no need to make this longer than it already is) and how its difference didn't seem to be as watered down to me as it first appeared.
TL;DR
The class system doesn't seem as redundant as much as the job system (personally) feels like it doesn't really fit the way it's currently established, doesn't matter though!
Oh! and a quick question. With the last month or so of playing, does the level of my pugilist or archer effect what base INT and PIE I'll have,? Ex: If my Pugilist is only level 10 will it have less of an impact on BLM base INT than say the amount of impact having a 50 Pugilist would? I should probably search this, probably will, but I'd figured I'd ask while it's on topic. I could be way off here, but I'm not too concerned with being Noobflamed.