The differences in tone and paint scheme is intentional, although I want the colours to be similar, I want these beasts to be a bit more individualistic than their smaller cousins (and the Haumea should be be even further differentiated). I might even go so far as to add some battle scars in the end, to further reinforce the fact that they are massive war machines.
Game wise, the Sedna fulls the much needed role of main punch in the force, as the mediums lack the close up firepower (both with Main Ordinance and CQB) to match most opponents. Hence, the Sedna should probably be used in pairs, although I've been experimenting with only using a single as a oversized APC for my infantry, to try and grab the secondaries. The downside to this is that I then have to try to punch with a Lamana squad (with Sirsir support, of course), which tends to result in a battle of attrition that the Aquans are ill suited for.
I'm going to give it a few more tries, before giving up on the idea...
Speaking of large things, Spartan released some images of the Aquan Leviathan Helix last week:
The one thing I'm not sure about is the feet, but I've got some old Chironex Cruiser front pieces that might make decent 'talons' instead (sure, I'll have to remove about 80% of the bit to make it fit, but... ).
Now all I'm waiting for is the Recon helix....:-D