Power Phat vs Power Fuel

Can you tell me what the difference in these two products and opinions on each.  We have some younger steers this year, and a american trying to fatter a bit quicker although shows not till Jan-Mar '11.  Should we be feeding this now or wait a while.  Calves weighing from about mid 600-800 lbs.  Appreciate it.

bump... I know someone has something to tell me on this thanks  :-\

I've never used Poer Fuel but have used Power Phat for several years and luv it... I don't think that it is to soon start giving your american catlle a pound a day at this time... If you read quotes from Steirwalt or talk to him I think he will tell you they start all there steer calves on PowerFuel asap but these are cooler kept calves for the most part...IMO it is better to have those americans fat early and not stressing in the end trying to get them fat...I also think that getting them fat early will help slow the frame down a little if you have one that is a little big framed...G-Luck