Ugh brings up a good point about noise. Perhaps the single-fan solution makes more noise as it tries to cool the smaller PCB, whereas the dual-fan solution is going to produce less noise as the RPMs are kept lower. Then again, I really have no idea as I've never used a single-fan GPU like that (non-blower style setup).

Single-fan setups like that are generally preferred by people who have small form factor builds, or even something like an HTPC.