This is a review comparing EVGA and MSI GTX460's, as well as a few others. The EVGA Superclocked card they test is not the EE (External Exhaust) version you mentioned. Apparently, the EE version has a blower type cooler that is a little bit louder, but maintains cooler overall case temperatures.
The key, however, is to note that the EVGA Superclocked in this review has a maximum overclock of 880mhz, while the Cyclone only gets up to 831mhz on standard voltage. What this means, and the article refers to, is that the EVGA Superclocked editions have better "binning" and are selected after passing a higher level of quality control testing. Add in the 10 year warranty and step up program offered by EVGA, and I would go for the EVGA card.http://www.guru3d.com/article/geforce-gtx-460-review/1
Tom's Hardware also did a direct comparison:http://www.tomshardware.com/reviews/geforce-gtx-460-roundup-gf104,2714.html