A few notes on why I'd stick with CloudFlare personally: In my experience the NS transfer takes 20 minutes tops. Part of the idea with CloudFlare being nameserver on down is that DNS is a great thing to hit if you're performing a DDoS attack.
Also, CloudFlare does offer the offline mode feature, it's called "Always Online". It's also free for more than 1 page, unlike the Kloudsec one.
It also seems weird to me that they bill for their "webshield" on a per-attack basis... someone firing an automated scanner against you could be costing you money big time.
These guys also don't have the same reputation as CF for being bulletproof (though I haven't heard bad things about them yet either) and they have some limits on their free plan which CF does not have.
Interesting though - always glad to see some competition brewing. I know where I'm taking my business if CF steers me wrong somehow. This looks a lot cheaper than other alternatives.