heh i read that as "rather subpar power" first time round and was preparing a solid butt-whooping 
Apparently some slot it with acc, but i cant say i've ever seen it miss. I think the acc might be for the immobilise it does but you have roots for that, or thorntrops if you must. I must say on my duo team of my plant/thorns and my friends ice/rad corrupter i get most of the kills due to creepers. It might not look like much damage but it seems to add up nicely so i'd try slotting 3 damage if you got slots spare.
If you have a very tight build like most doms do, or don't solo much, just stick with 3 recharge, it's great as it is.
I miss him in the weeping of the rain;
I want him at the shrinking of the tide;
The old snows melt from every mountain-side,
And last year's leaves are smoke in every lane;
But last year's bitter loving must remain
~Edna St. Vincent Millay
Well, the Prima guide states creepers as having 100% accuracy in all their attacks. Doesnt appear to be autohit though. Weird.
I seem to remember that it does an acc check when it spawns vines per enemy. Can't remember the source though, so don't take that as gospel. I slot mine 1acc, 2 dmg and 3 recharge.
Thanks folks.
Now,
Can anyone explain what it does? 
Was so wishing you wouldn't ask that.
Well it slows, it damages, it immobilises, it spawns a vine for every foe i think and more when they die. It will follow you around through missions and affect different mobs, so is effectively perma with hastenand 3 recharge.
Most important thing - IT TAKES AGRO! Single most useful thing about CC is you can spawn it on a mob and they will all attack the creeper patch as it counts as a pet and is targetable.
Plant is such a safe primary, creepers completely soaks up the alpha and seeds recharges really quickly. Brutes can hate me in teams because my dom is the 'fury-killer' (tm). You can open in complete safety even against high lvl problematic mobs like malta or longbow etc. Unless the vines get killed really quickly and they turn on you, but i've never seen this happen in 40 lvls.
Creepers>seeds of confusion>roots>fling thorns, then the odd attack while they all kill each other, ur aoes damage them all and you get a very high percentage of the xp depite confuse with little risk.
I miss him in the weeping of the rain;
I want him at the shrinking of the tide;
The old snows melt from every mountain-side,
And last year's leaves are smoke in every lane;
But last year's bitter loving must remain
~Edna St. Vincent Millay
Agreed, I have taken on 6man spawns with my Plant/ Fire with little worry. Creepers>Confuse>fiery embrace>Fire Breath>Bile Spit>consume>attack chian. They're all dead, you've got full health and most of your end 
Ok chaps, any advice on how to slot this rather superb looking power?
I want it up as much as possible so thinking 3 SO recharge. What else needed? acc? damm? end? immob?
Answers on a postcard, or preferably by replying to this post