I'm torn. I have more dinosaur models than I can use in normal games. Storm of Magic opens up new excuses to use them. But a Storm of Magic LM army supplemented by Steggies, Carnosaurs, and Cold Ones isn't that much of a departure from a normal game which makes me wonder why not just play a normal game? I'm sure people will say that certain monsters get you more bang for your buck, but I don't see a whole lot of difference between a pack of Cold Ones ora pack of sabertusks. Or a stegadon and manticore.
The big difference is speed and flying. Two things the lizardmen lack in spades. For my Storm of Magic tourney I'm using my high elf dragon and great eagle. That combined with terradons makes for a might strong and fast flanking army. On the cold one issues it feels for 11 points cold ones are better than the riders at 35 points 2 attacks at S4 vs 3 attacks at S4/5
They're not that great in either context? Magic > everything, as always (but especially on low Initiative models). Worlds of difference. Cold Ones really just have Frenzy and Fear going for them, massed S4 attacks we already have (on Cold-Blood real infantry as well, and fulfilling Core). I'd actually be more inclined towards Sabretooths, as their ambush ability lets them gank warmachines and shooty infantry in the backline. Eagles are also pretty badass, S6 flaming attacks with ASF is pretty brutal, and they have the speed to flank and cause problems (they make Terradons look like flaming garbage, literally). Truth be told though, if you wanna not lose at SOM (its pretty random so winning is more a case of trying to stack abilities and hoping you don't roll on the Miscast of Doom chart it has), I'd load up on Wizards. A Zoat, a moderately outfitted Vampire Lord and mandatory Ghoul pack can be squeezed into a 3k game, giving you a Life caster (so you don't have to take it on Slann) and a Metal or Death caster (for 'Golden Globe' or 'Purple Sun' respectively). Magic still dominates in SOM, like it does in normal games. Also, having fighty casters (Zoat does ok and is pretty tough, Vamp Lord is a god) helps a lot, because people will be gunning for them on the Fulcrums.
In my SoM games I will almost always grab my Zoat, a Dawnstar sword and either a Truthsayer or the Llamasu. Lvl 3 or 4 Life that is amazing in a forest, a decent Beasts caster or Fire one (and very defensive with the Llamasu). The more lores you have available the better your chance of getting something in ascendance. I slap the dawnstar on a scar vet w/ cold one. Then depending on the build you want to go with you can have a 1+ rerollable armor w/ extra goodies or 1+ Armor, 4+ ward and 8 always hitting, always wounding attacks at str 5 tear through almost any unit.
I Like the Emperor Dragon with one wizard level. I usually go with frost as ASL breath is useful. At S and T 9 and Ld 10 there aint many wizards that can stop him from taking a fulcrum. I also like the harpies. Poison and/or Killing blow with two attacks and fly can make for a bad day for all sorts of elites. The Thundertusk and its always strike last aura is fairly brutal to any one with a 2+ I going up against Saurus