I've never had a problem with taxis in Singapore, the taxis provided by Comfort indeed makes travelling very comfortable. I especially like the sleek design of the blue taxis, and the bolstered seats, fragrant air-con within the cab while zooming by the roads makes travelling awesome, if you can refrain from looking at the meter that it.
The only problem I had was with the cabbies themselves. Some of them are cunning, once there was a cabbie who took a roundabout route just so that the meter could increase further, despite me pointing out the shorter alternative route to him (I was rushing for an appointment). Hence, not only did i end up paying more, but I was late for it, hence a bad impression. Another incident would be the ogling, nothing is more disturbing than seeing an uncle staring at you hungrily from the front mirror. Thats the experience a female friend of mine had when we went for an outing, it made her paranoid for a few days of taxis.
Overall, the standards that Comfort has is reasonable and satisfactory. However, the service standards of their cabbies have to improve and they should try to keep fare levels at a reasonable level.