I bought last month a IC by ATM, I have not time for try before and after the power, but the feeling at the drive is much better and belive me all of the time to I do something my feeling is not very generous also if I gain 10hp, I bought the ATM because it's the only one to had a little more attentions for the air flow, i was happy by one side and not very by one other because the IC its very heavy, also don't have any plate for the original supports and particularly because the tank looks exactly like the tank in all intercooler, 3/4 mm thicker in some spot in the both entrance, that make one very bad step for the air to need to cross easier the IC and if you pay attention for the core and you want show for all USA to your IC are more innovative you need also to work better for the details! The price is little hight in line with the other IC, but this one is US made, than no import tax no shipping from other country, then the old price to that had 450$ was more appropriated for this model, in the same time the owner of ATM it's very nice and if you have a particular request him will be help you.
I spent almost one hour for grind the in and the out for delete all step and now i'm sure to will be very hard to find a better intercooler for the performance. I had many turbo cars in my garage and one of the most difficult part for run fine the engine it's to find a good intercooler. Unfortunately the Mini had one horrible IC and find one worst than that will be very hard. Than it's easy for some brand make IC and show the benefit.



Inside you can see the tecnique to ATM use for make smoot the entrance In the Channels



This is how look before grind with the dremel the in and the out




This is how look after grind with the dremel the in and the out

 

It looks suspiciously like the Helix intercooler that's been around for ages.

 

It was initially advertised as the same intercooler as well. The post above was a lot of work for a $550 intercooler. Pretty sure it isnt US made as well.

 

The price in the atm website is 625$, the work to I did it's almost the price to you need to do for all intercooler made by casting, those usually have a lower price for that, in the same time if you buy forge, they use Sharp edges everywhere bad for every ic, if you buy Wagner the IC is tube and fit and the in and the out are the same of mine (ridiculous), Alta looks right by side of the same in and out, but if I need to modify the bumper I would like to buy a better ic for half price, a ic with less than 400cfs at 2psi it's bad. The Helios and the atm are good (on the paper) for that special.

 

ATM is the designer/manufacturer of the original Helix intercooler. ATM makes a big deal of the bullnose bars on their intercooler, which theoretically should improve airflow but in the real world I'm not sure how much of a difference it makes. No matter what it is a quality product.

I chose the Wagner, it is not just something thrown together that fits in the space but engineered, designed, built, and tested. Plus they publish their data. if the Helix 2nd generation had been available at the time I would have seriously considered it for the same reasons. I have done datalogging before and after installation that shows the effectiveness of the Wagner at keeping IATs low.

There are plenty of cheaper options available, do a search and you'll find lots of threads for cheap eBay knock-offs. But you aren't going to find an engineered, tested, well built intercooler that really does the job for half price. Pay your money, take your chances.