Same with yours, I'm going through it now too. Ya, I study a lot of Japanese linguistics. I always like understanding why something is.
I particularly like dialectology and Classical Japanese.
Yes, the differences between the two conjugation systems if you will are purely stylistic and limited to their respective situations, of which obviously the use of suru and its normal bases is dominant today, that is unless you get into dialects, which I do. 
The traditional bases of す
未然形:せ・さ
連用形:し
終止形:す
連体形:する
已然形:すれ
命令形:せよ
Of course, we know that the first is used with endings like ん、ず、ぬ。
さ Is used with things like -れる。It is limited.
In Modern Japanese it gets more tricky
未然形:し、さ、せ
連用形:し
終止形:する
連体形:する
已然形:すれ
命令形:しろ・せよ・せい
The emergence of three 未然形 is rather reminiscent of the multiple sets of bases seen for other things historically in Japanese. This gets muddled with other dialects. From what it appears to be, it depends on the region which of the three are more prevalent in its conjugations.
The Western Dialects, for example, still tend to use the original se- base for negative endings.
Now, the problem comes with suru-verbs. I like to break them into different kinds as I've discovered restraints to patterns, using seru for the potential.
This is essentially like I said earlier treating something like 愛す as one morpheme. This in linguistic jargon means it's deemed as one unit, although we can clearly separate it as one part being Sino-Japanese and the other being native.
Thus, a "new" verb is created. Of course, it's always existed, but the change is in classification. This most certainly developed from overgeneralization of the rules, seeing that it ends in su, why not conjugate it like all the others?
This, though, has its restraints. You never see something like 勉強せる.
You also doesn't see 感ぜる。
You can, though, see 感ぜられる。Though, if this be used at all, it would most likely be the 受身形。
A lot to go through and consider. Overgeneralization has in many dialects greatly reduced the number of verbal classes.
Some dialects find a way to make basically everything an 一段 verb...if only
I'm only 18, but I am a Japanese study-holic. I would love to have discussions about Japanese with you. I actually really want to go to Nagoya. Alas, money....I'm stuck in the states.
I must warn you about some things concerning the site. Some lessons are incomplete or not finalized and may be very lacking or monstrously large. This is just because I'm undergoing a painstakingly long remodel project that will take perhaps half a year to finish, but some of the immediate issues are not going to be long lived, or at least that's the plan.
Last edited by imabi (2012 October 31, 5:32 pm)