So first off I’ll start by saying that I love greatsword, I’ve always preferred and played warrior archetype classes with — you guessed it — greatswords.
Greatsword for warriors in GuildWars 2 is amazingly fun while playing solo. You have great mobility, and phenomenal damage — both AoE and single target.
The Problem
The major problem I (and many warriors I know) is that our highest damage ability is essentially a 3.5 second root / self-cc on a 6.5 second cooldown (with a 120 degree cone of damage). In a game where there is no ‘trinity’ and consequently no tank, unless the boss / mob is ranged, it moves — constantly. The delight of greatsword quickly wanes when all you’re able to do is chase around a boss autoattacking and every 8 seconds Whirling ahead of him, and every 12 seconds throwing your greatsword at him.
The warrior archetype is usually either a highly mobile berserker or a heavily armored tank with a shield. Spending around 60% of the time essentially ‘self-rooted’ goes heavily against this archetype, and isn’t very fun when the boss doesn’t like to stand still for you (teehee).
The Suggested Fix
Could you please consider making Warrior Greatsword ability Hundred Blades an ability that at least you can steer/turn/move a bit with. What you did with Guardian Whirling Wrath is better, it’s 360 degree AoE that allows you the freedom of movement. I’m not asking for this ability, I’m asking merely the freedom of movement for Hundred Blades.
Often times you will get into the prefect position with your enemies arranged in front of you and you start Hundred Blades, and they all move behind you or just out of range, forcing you to cancel and autoattack for 6.5 seconds waiting for it to come back up. Often, this will happen again, and again lol — especially with fights like Champion Abomination — when he only stands still long enough to get 2-3 of the 8 attacks Hundred Blades does while he smashes a player.
This is mostly a Quality of Life change. I’m asking that since there is already a precedent of making an ability do different things in PvP and PvE in GuildWars 2 — i.e. Guardian’s “Save Yourselves” functioning differently for PvE and PvP (not to mention the proud history of GW1 where scores of abilities functioned differently) to please, please give Hundred Blades some mobility in PvE.
Again to reiterate, Do Not change this ability in PvP, just PvE, pretty please 
The Bug
Finally, I’d like to include the fact that at the time of posting, you cannot dodge-roll out of Hundred Blades, Rush, and Whirlwind Attack (number 2, 5, and 3 greatsword abilities respectively).
Why does this need changing? Well for instance, some abilities in dungeons pretty much can one-shot you, and for players who use dodge-roll on a keybind and not use “Double-Tap to Evade” not being able to dodge-roll during these abilities cast time can be deadly. You have to break the action’s cast time first (by moving any direction with Hundred Blades, and currently no way to avoid Rush’s 2-second animation before you can dodge-roll). Whirlwind Attack less so because you avoid some damage, but still lots of stuff can kill you / stun you and kill you while Whirlwind’ing.
Finally
Thank you for reading, hopefully it’s easy enough to read and isn’t just a wall of text, and finally — I love your game Anet, you guys and gals do great work!