Well, for people like me, I have absolutely NO MP problems.
Sieg isn't meant for skill spam. The reason why I adore sieg is the fact that I can dish out thousands of damage on combo-able monsters using level 1 Kicking and level 1 Crosscut and comboing them till they die.
As for the uncomboable monsters... most of them freakin flinch, and my Sieg's DPS with simply AS sp sp is simply wonderful. Probably faster than continuous lvl CMS no-cooldown spamming...
To be honest, I would never expect a sieg to use Dfist, IH, nado, and CMS in less than 60 seconds unless it was a boss you had to kill quickly, or if the Sieg was all alone facing a huge gigantic mob (Sometimes, skill spam is sometimes worse than just AAAAA spamming in particular mobs. I'll give you an example...Troll mobs in ep 5. A friend of mine loses a life skill spamming the mob, while my other friend doing the same stage in a solo beat the whole entire troll mob with just AAAAA).
If you see a combo-able monster, don't go Dfisting it... If you see a mob, don't immediately go IRON HAMMER them. Be more conservative. Sieg has more than just Dfist, Iron hammer, and RB skills.
If I see a mob, I don't dfist if they're comboable. I level 1 crosscut them (hey it has a nice broad range and it knocks a nice number of them down!), then I just down attack them, back dash cancel and down attack them AGAIN, and THEN use CMS. If you have max MP regen (no AEH or AWD set), the amount of MP you gain from crosscutting them and down attacking them could be around 50 or more MP, and continuously saving that much MP every time you crosscut and down attack spam the monsters gives a very nice overall saving of MP every 12 seconds.
I don't really know how to say it, I guess I'm screaming COMBO THEM IF YOU CAN...
A dfist at the high 60s does over 1000 damage. AAS AAAA kicking S *shift* aaaa Crosscut sp AAAAA to a combo-able monster does over 2000 damage I suppose.
I dunno.. If I wasn't bombarded with homework, I would fraps an upper/lower raid that I'm in and show you my MP management.
And to be honest, I've played every character available to GLunia already. None of them except Dainn and Sieg intrigue me. Yuki, Dacy, etc. have a really nice DPS abilities, but they don't interest me at all, even when I can perform wall-bomb combos with dacy (AAA needle carpet A Bumpy dash Fuzzy whirlwind Summon Catchvee then use Bomb, while pressing 'End' to kill catchvee for that extra hit. It doesn't interest me anymore.