redeemer :
Mantle supports GCN so there is a bigger customer base, G-Sync is a niche product $200 for a DIY Kit and Monitors will cost $499+. No doubt which will have the greater adoption.
Both technologies are a boon for gamers
Both technologies are a boon for gamers
Do you think there are more Radeon 7xxx & R9 2xx cards than Geforce 6xx & 7xx cards?
They should be quite similar in size. Only G-sync works for all games, and Mantle doesn't work for any games yet. The downside is G-sync requires you to purchase a monitor, the good news is all games will support it.