Oh crap. this always happens whenever i join a forum, i forget to check the date. -_- the problem with it being lvl6 for that is that i cant be assed getting the big slow marza up there.
Personally the Kol is my favourite, however I 90% build an Akkan first but my second is always a Kol. I usually follow that with a Sova. i rarely build Marza's, i just find that they take a long time to do nothing. their radiation gun is kinda useless and even though they are useful planet bombers I only build one. the Dunov is my late capital, i get a couple before my killing blow to support the fleet. i will usually have mostly Kol class vessels. thats my tho