Alright so I'm back a little later than I expected but here is what I have learned in the last week and a half, as well as what i learned reading through all your helpful posts:
The major change i needed to make to be competitive in against all comers is switching to infantry. I'm not sure how you, Tweedz, got so lucky as to not loose a bunch of serpents. But when I played against my friend's proxied tau (we were trying things out) he consistently glanced to death two serpents per turn. Resulting in 4 of 4 wrecked serpents by turn 2. This is untenable in an 1850 list where my serpents are my major deployment mechanism. I mean its S7 spam these days, why does reducing pens to glances even matter? People are hoping to glance you to death.
5th ed for me was everything IN armor, no wounds on the table, just AV. I took an about face on this technique and replayed the same opponent list and fared much better.
To help compare my two lists we set up identical terrain, with the same mission, against the same tau list, with me deploying first and then him 'seizing' as he did last time. I intentionally deployed my army aggressively as if I thought I had first turn, so I would be properly on the back foot when he totally "seized" again. In other words I recreated the first battle, but with a new army for me.
His list again was:
two hammer heads, one character
two path finder squads
3x missile spam broadsides
3x fire warrior squads in devilfish
some special character and an ethereal
my list was:
HQ:
Spiritseer
Troops:
10x Stormies
10x guardians, SL
9x GJB, 3x cannons
Fast Attack:
3x Vypers, Star Cannons
9x Shining Spears
Heavy Support:
3x D-cannons
9x Reapers
--starshot missiles for everyone
--Exarch, Fast Shot, Star Shot missiles
Fortification:
Bastion, Iccarus Lazcannon.
this list has been heavily tweaked since formation, so it might be slightly off. The idea here is to put my reapers in the Bastion's tower, use the spirit seer to get them that great cover save and the Exarch to double fire the lascannon with a bunch of Krak missiles as support. My jetbikes and vypers aggress to disrupt things. My D-Cannons are not in this list to fight tau, but instead deep-striking things like Space Marines. they go in cover near my bastion and keep things away. The stormies fire the heavy bolter and provide light counter charge.
So he stole that initiative just as planned and was remarkably ineffective at killing my stuff for that turn. Missile swarmed a one or two reapers to death, nailed a few guardians off my support weapons, killed a few jet bikes. On my turn i advanced all willy nilly, stunned the hammerhead because it encrouched on my D-cannons (poor rolls) and my reapers nuked a devil fish.
by the end of the game I may have been able to grind out a draw (only made it to turn 4, then shop closed) but I definitely did better. He had two squads of fire warriors left, no devilfish, one hammerhead. two pathfinder squads and the missile-sides. I had a few reapers, both guardian squads, and two working D-cannons. (2 guys, 3 platforms).
Then I ran a slightly modified list against IG, massacred IG.
I'm tweaking it a lot still, but the reaper star strike spam is glorious and one of the cheapest ways to get gobs of S8 on the table. Also, did I mention how awesome bastions are as a core piece for an army? I'm going to do a big conversion/scratch build project to create an eldar bastion.