Downloaded and installed Darkfall yesterday, and logged in about 6 hours of play so far. I have heard the comparison to Ultima Online and Lineage, but having never played those games, I can only say it reminds me of Mortal Online.
I have played many MMO's staring with Dark Age of Camelot, and missed the early era of games that had little guidance for a new player. Most have extended tutorials, expansive in game manuals, and rabid fan bases who update any number of player created info sites or wikis. Darkfall is very minimalist. I couldn't find the command to quit a group for the first 5 hours of play. The UI is functional but not user friendly, the control scheme is counter intuitive and seems to make things more difficult then needed. The graphics are dated, and tend to a darker palette.
But as you get past these things, you find a small hidden gem of game deep inside. It has given me the feeling of an adventurer in a wild and dangerous place. Caution is needed for every encounter, wonders are hidden across a giant expanse of land to explore. You never know who or what you will face, and they never are sure about you.
In some ways this is similar to Eve Online, but different. In Eve you have so much info the key is finding the right bits and pieces at the right time to make good decisions. In Darkfall it is not having enough information, so you must use subtle clues, and caution to win the day.
I don't know how long I will play in Darkfall, but I must say I am enjoying it so far. It is good to know that not all MMO's are the same, that there are games that have taken different paths. No path is better than the other, just different, and we as gamers benefit from so many paths to chose from.