f13.net

150mm Light AC I (http://www.eve-online.com/itemdatabase/shipequipment/turretsbays/projectileturrets/autocannons/small/485.asp)
150mm Light AC II (http://www.eve-online.com/itemdatabase/shipequipment/turretsbays/projectileturrets/autocannons/small/2881.asp)

I personally don't see a huge difference except for the base damage modifier being 17% greater on the Tech II. Considering I am 7 days from Small Projectile Turret V if I start now, I have two questions:

• Is that 17% base modifier just that good? Should I be frothing? ;) Seriously, it seems like it could go either way for me.
• If not, does the +2% to that modifier from each level of Small Autocannon Specialization I push it over the edge from Good to OMG in comparison to a similarly skill-modded AC I?

It is the 2% that pushes it into OMG mode.  Still I would NEVER EVER equip techII stuff on a non techII frig/cruiser unless you are doing mission running in safe space.  Otherwise you are just asking to have money removed from the ole wallet.  Better to use named drops from rats for a little boost, which means you need to go hunt rats of the race of whatever type of ship you are flying.

Ok, cool. I'll wait until the Cruiser for Tech IIs. No idea how long that'll be. I'm thinking Rupture.

I'm running level 3 mission in my Rupture atm, using a combination of 3 heavy launchers and 3 light T2 artillery. Don't know about the autocannons, but the arty does as much damage as T1 mediums.

Also remember that only T2 guns can use the new T2 ammo, and that really pushes business into "omg" mode.

Oof, you shouldn't be specializing in small autocannon yet.  Skills like that generally only matter for high-end pvp. 

T2 150mm AC's are cheap and VERY effective, especially when you load them up with Barrage S amo.

Going to focus on the remainder of my support skills for now, then move into L2 missions once I learn Connections. I can access some L2 agents, but they're all Empire agents at least 40 jumps away  :-P

Small Projectile V is a 7 day train anyway.