Are all batteries from DX crap?

[Big Red One]

I have bought batteries off dealextreme :green: :sick2: specifically a pair of UltraFire 18650 3000mAh 3.7v with protection and TrustFire 16340 880mAh 3.6 v with protection. I did so according to the reviews on the batteries with 4 or 5/5 ratings by various buyers. To my horror a lot of the posts here concerning batteries from DX stated they are very unreliable and at most, a waste of money. So what's the real rating of the above batteries in terms of mAh capacity and longevity from an expert in this area. Thanks..........