Both are very well thought out and reliable kits. The SOS definitely has the advantage of time and mileage- there are several on the road with significant mileage and no issues. Hugh's "Charlotte" is probably the most famous- well over 100,000 trouble-free miles on the SOS system. Using one small turbo for each cylinder bank is closest to Honda's own turbo design for the C30/32 (LeMans GT1), as it provides crisp throttle response and better low-end torque with minimal lag. I would recommend getting the kit installed and tuned at SOS directly. Almost all of the turbo problems we've seen over the years here on Prime can be traced to a DIY install, poor tuning, or a shop that makes mistakes.
The ASM kit is also quite innovative because it uses a twin-scroll single turbo tuned to the high compression of the C30. AWM in Finland designed this kit and they are legit- no corners cut here at all. Again, I would recommend going with the tuning/ECU option they recommend for your application.
As for which one is "better"? That depends on your intended application and, quite frankly, who installs and tunes it. If I were racing, I'd probably get the ASM. For a street car, I'd go SOS. JMO