I'm researching DDoS solutions, and have been looking at F5 and Radware. Are there any other solutions I should be considering? Please also share insights from Gartner.
I highly recommend Cloudflare. We switched from Akamai Prolexic to Cloudflare and couldn't be happier. We also got the worlds fastest DNS and speeded up our site load times with the 200+ edge locations near to our customers.
You can have a look to Imperva Cloud WAF, the anti-DDoS mitigation is under 1s and works very well. I observed a lot of DDoS attacks that were well managed (even not seen by the customer) by Imperva, I can recommend it (try it with a trial, you'll be able to have your own opinion).
If you need it, please find article about Gartner Magic Quadrant for cloud WFA (including DDoS mitigation tools):
A10 Network Thunder TPS
In case you are considering a fully automated Cloud solution for DDoS Protection, BGP based, I can help with information on Voxility Anti-DDoS.
How do these two products compare?
If you have a CDN, does it mean you don't have to worry about DDoS attacks or will hackers still succeed in carrying out DDoS attacks?
I'm a VAR/System Integrator and I don't see any problem once you have Cloudflare.