Arelith

So lets start with a brief explanation about normal whirlwind.

-It is a FULL bab attack against all surrounding enemies within 5 feet (although, I'm 100% sure it is determined or just affected by weapon range. For a fist monk it definitely feels like larger radius than a scimitar).
-It is an instant action, sort of. It deploys instantly but has an animation of 2-3 seconds in which the character is locked. But the response is instant when clicking the button. It leaves room for creative use and the player's skill is somewhat relevant in timing it right but it is not an instant action as blinding speed is, for example.

Now, to put it simply..

Improved whirlwind is a downgrade.

-It is still a full bab attack against all surrounding enemies, no differently than whirlwind there.
-The range is increased to 10 feet, but as I said, it is probably subject to weapon's range so it's hard to tell if the increase is actually to 10 or to even more. So that's an upgrade on that aspect, at the very least, I will admit.
-Most importantly, and the part where this feat is a downgrade, is that it's a normal full round action, as if you were using a wand or any item special ability. This means that the moment you click the ww button your character stops acting and stands in 'between actions' until the end of that round, in order to do the whirlwind next round, eventually ending up costing you no less than a full round and up to full 2 rounds to cast. Also, because of this, player skill and lag weight more.

Suggestions:
-Give PC monks who are forced to have it, the option not to use it, but a toggle command that switches between improved and normal WW.
-Give said PCs the option to have it removed indefinitely by a DM, until (if) it's improved one day.
-Remove it from monks.
-(EDIT:) Remove the cooldown from improved ww. It will still take a full round to perform the action, thus 6 second cooldown.

I'd really like to hear your opinions if you've had a different experience with improved whirlwind and found it an upgrade. Maybe I'm missing something?

(some typos edited)

I've played a DEX Rogue/WM on another server where I found moderate success with Improved whirlwind for PvM. Basically, I amassed a few spawns, clicked Expertise/Imp Expertise on, and stood in the middle of the spawns crowding on me while spamming Improved whirlwind, doling out some crits to the backlines at full BAB without them being able to hit me. It was among the best non-caster solo strategies I deployed. For spawns with archers or mages, I'd stealth to take them out etc. Mind you, there were only two dungeons where I had to resort to this for solo, because the mobs' disciplines were too high for KDs, which would've obviously been the more effective tactic. I also gained style points from that spicy VFX and was regarded the veritable working class hero.
/endanecdote

On Arelith, though, the epic feats are more contested due to the OPness that is Blinding speed, blessed be thy name.

If Improved whirlwind were available to non-Dexers, I'd imagine the above strategy were more operable, too.

Anyway, the main thing that vexes me about the problem that the OP pointed out is the inconsistency between Whirlwind and Improved whirlwind functionality. If possible, they should be made to work the same, i.e. either semi-buggily as normie Whirlwind does, allowing you to attack out of round sequence for a schweet opener or making like a chicken while kicking about, or then the clumsy full-round eating Improved whirlwind, which would admittedly nerf Whirlwind and prevent its most general application.

An additional solution to the Monk problem a la OP would be to not make Improved whirlwind overwrite normie Whirlwind, so you would retain both combat abilities like Expertise/IE. I'd personally find the consistent functionality more satisfying, however.

I suppose removing the cooldown from Improved WW could also be a good a way to make it useful, somewhat. It would still have an effective cooldown of 6 seconds because that's the length of the ability initially but it would still be inferior to normal whirlwind. I do not suggest to touch normal WW in any way. Its one of my favorite feats in this game.

This is really interesting because I must be the only person that whirlwind does not work for. I see lots of people say things like spam whirlwind for free attack...

I have a very specific window that I can click whirlwind or it’s a total crap shoot, and that’s immediately after the third flurry. If I use it anywhere else I lose the remainder of the routine. For example:


Flurry1
Flurry2
Flurry3
Whirlwind

Flurry1
Whirlwind
Dead action
Dead action

Flurry1
Flurry2
Whirlwind
Dead action