Alright, as HCDR said before, the brothers from Kalmah do have great writing, I love their style of melodic metal and I've liked them for awhile now. The thing is, yes, they get very repetitious and repeat the same melodies over and over again, which is fine for it's genre, but still lacks the ingenuity of Alexi's writing in COB. Furthermore, Kalmah, while having awesome solo's have more of a raw feel ot their soloing, and honestly I don't really like the way they shred sometimes. It's almost too raw as though they just didn't feel like perfecting it (Even though it did make it to the final cut, and it probably is the feel they wanted).
Alexi on the other hand serioulsy just writes kick ass riffs, dynamic solos and just blows you away, not to mention his own vocal stylings amidst so many others that sound the same. I just think that COB is a better band, both creatively and just listening to them to enjoy it.
Although, I have discovered that listening to Kalmah while driving to my girlfriend's house is fucking awesome. It's great driving music. And Heroes to Us, Hades, Alteration, and Swamphell are awesome. So are many other songs.