I finish one bottle of this ECA supplement and i was pretty good results i start 84kg (12%BF) and i get down to 80-81kg (8-7% BF), it didn't give me any crash and i notice a small difference on my workouts. As far as my workout plan i am doing 5 days resistance training and 2 days of 60 min cardio. Not to be mentioned that i was eating super clean and i follow a low carb and fat diet.
Today i receive the thermogenesis ECA stack they say it's a lot stronger and better value for money (you take 1 capsule instead of 2 and has 120 over the 90 that heat has), i am going to write a review about this one too after i finish it.

Overall HEAT is a very good ECA stack a little bit pricey though

Hope i help,
(Posted on 5/31/10)

The Best ECA stack formula by far, I have tried a few of the different ones available from this site and this is by far the best. I have been on these tablets for 2 weeks now taking two tablets when I wake up and 1 or 2 two more at lunch depending how I’m feeling, They give me tons of energy, I'm never hungry, weight is literately dropping off me, and they don’t make me have random dizzy spells that I have had of other products.
They don't not affect my sleep as others I have taken in the morning and been up all night with a cracking headache the next day.
Defiantly my miracle pill.
(Posted on 1/23/10)

well, I have used in the past, all the expensive & quality fat loss supplements ( even Lipo- 6 Black).The good thing about ECA stacks is while you are on dieting hard to get rid of the law few inches off your love-handles/ waist, we need to even push ourselves harder to do the dreaded cardio relentlessly, thats where these ECA stacks help and score over the normal thermogenics ( even the best companies cannot compare the ECA stack, because at the best they just have 6 main ingredients to play with, they might release many so called HARDCORE versions etc with a thing tweaked here & there ).
ECA stacks give you that extra push to continue with the cardio while on diet without the fatigue ( though they do crash really bad, as the ECA stack weans off after 4 hours) still if you are FOLLOWING DIET & DOING 4 DAYS WEEK Quality cardio, by all means ECA STACK IS 4-5 times better than the best thermogenic ( I mean the usual ones the, BB companies sell ).
MINUS PART:
YES, there is a MINUS SIDE TO THIS MIRACLE ECA stack, they might give major crash after the effect weans off PLUS THE WORST PART OF THIS ECA STACK IS= TOLERANCE. You develop tolerance levels to the continued use of high dose ECA stack, plus it does stress the CNS ( centeral Nervous System a lot ) & if you are also drinking coffee during the daytiem with ECA stack you are even more at risk of becoming stressed & easily annoyed etc.
So DO USE ECA stack if you CAN DIET & REGULARLY DO CARDIO ( even Moderate) BUT DIET IS MUST then for 6-8 weeks ECA stack will show its amazing effect, AFTER THAT QUIT /AVOID taking any thermogenic for 6 weeks. Thats ideal way to fully see what wonder this ECA stack can do. Plus NEVER forget that ECA STACK wont do a thing for couch potatoes, because only while regular activity can you tap the ECA stack add DIETING to that you WILL LOSE 2- 3 inches by all means ( don't worry LBS they will shed, the hard part is INCH LOSS).
So use ECA but do your bit & your own homework. (Posted on 12/29/09)

I have no idea what the previous reviewer is talking about. Its one century's more expensive eca stacks, BUT its well worth it. I love the yohimbe in it, although i hear yohimbe is not for everybody. It works wonders for me! :D (Posted on 9/15/09)

Been taking this product for one week. But absolutely no results. I'm definately not losing my appetite and feel as tired as i always do. Really disappointed. (Posted on 8/31/09)