my build the past 2 gens, my favorite battle server build:
Strength: 21
Agility: 18
Hit points: 70
Skills to attributes: 8
Ironflesh: 7
Power Strike: 7
Shield: 0
Athletics: 6
Riding: 0
Horse Archery: 0
Power Draw: 0
Power Throw: 0
Weapon Master: 3
One Handed: 1
Two Handed: 133
With a MW Danish sword, you do very good damage, and the 133 WPF lets your swings feel pretty good in medium-heavy armor, I use a kuyak personally as I think its great weight-protection ratio.
Without the luxury of a MW weapon, you will find your swings hitting pretty weakly. This is especially true if you only have 110 WM and not that much power strike.
For a newer player, I would recommend 24/15, with 8 IF, 8 PS, 5 ATH, and 2 WM. This build grants you a great deal more survivability and pretty decent damage than a 21/21 level 30 build.
I tried the 21/21 at 30 build recently and found the lack of IF and WM to make the game a bit more frustrating and less fun to play, even if the 7 ath and 7 PS is a deadly combo. I think if you want to be decently fast an 18/21 or 21/18 build with maxed IF and some WM will be more enjoyable, and definitely more forgiving of mistakes.
For battle server, on the open maps, reach is king. The Danish Greatsword is the most used 2hander for a reason, its probably the best. You can fight off cav, abuse 2hand stab and keep up with the long polearms in "line battles", overhead spam in confused clusterfucks to often 1 hit kill people, and duel pretty effectively if you get good at footwork/animation abuse. I definitely recommend getting good with a great sword of any type, its the most well rounded 2hand class you can have.
For siege, closed maps, 1vs1 fighting, or if you are a very good blocker and attacker, the longsword shines. Its more difficult to use, but much deadlier 1 vs 1 if you can close the distance on an enemy. The problem in big battle server matches is you will be dealing with long spears/pikes and all sorts of support weapons and backpedalers, making it more difficult to use effectively until you are pretty good at battle awareness and technical skills like blocking.
If you like siege and like 2 hander, by all means you need to try out a great maul or mallet sometime. They are short and slow, but god damn are they fun and unique to the 2hand class.