Hotfeet is absolutely fantastic and it will do more dmg than imps.
You should be a bit careful about choosing it though seeing it has a massive end use...so coupled with /storm it can be a bit tricky. If you have an empath or kin with you then definately go for it.
Slotting would be:
PvE: 3 end red, 3 dmg
PvP: 3 end red, 2 dmg, 1 acc
SingStar:
"Extremists LOVE to fish to get us annoyed so we break the forum rules."
CRACK68:
"The origin of life wasn't planned either, should all life be declared a bug and wiped out?"
Lionsbane:
"You know me.Ever the realist"
Agreed with Arch on this its a great power but the end use is an issue and could be a severe one. Assuming you have good support its all good and will be amazing but I am not sure that I would take it on /storm without end buffs
Still worth a look imo.
Cheers,
White 
i went on Test the other day and tried it out with my fire/kin he doesnt have imps yet so the damage was much impressive, Flashfire, Firecages, stand with hotfeet on made for some very nice control/damage, when the mob comes to after flashfire you just hit cinders and go for another drink 
i decided not to go for it on my live toon though, allthough it was nice (and with being /kin the end wont be an issue after 35) it doesnt really fit with my playstyle.
so to sum up, great power, nasty End Cost.
@EU Brimmy - Union and Exalted servers
Thanks all for the replys ive taken it and enjoying it greatly.
Curently only has Do's in at present so cant wait for my So's and for my area control powers.
I've Hotfeet 3 slotted I think. 2 dmg & 1 End Red AFAIK. I needed the slots elsewhere and this was effective enough for me.
I was Rad though so AM saved my End a fair bit. I also ate a lot of blues pre Stamina.
Fire cages is an expensive attack so I only fire that the once to get Containment rolling.
Go destroy the Hollows spawns. Pick on mass groups of Blue guys and watch the XP roll in.
How useful is Hot feet not sure if to take this on my fire/storm troller.
Advice please if itsany good and suggested slotting.