The Twinings Ultra Spice chai tea bags are noticeably stronger than Twinings regular chai, but that's still not saying a lot in terms of strength of the tea. Even allowed a long steeping time in a small cup (6 oz) of water, Twinings Ultra Spice is just verging on an entry level of knowing it is in fact a cup of chai, in my humble opinion. I'd recommend using this one over the regular Twinings chai bags. Furthermore, to brew a 10 oz cup, try doubling up on the tea bags if you want to know it's chai you are drinking. Of course, for a traditional cup, you will also have to substitute some milk in place of 1/2 the water and add a bit of sweetener. But for comparison purposes here, I have brewed all the tea bag chai in water with no sweeteners.
Troy the Chai-Direct Chai Tasting Guy