I just had my 1uz injectors cleaned before throwing them into the engine, aside from being dirty outside, they looked pretty good but I still had two that dripped, according to the report from RC Engineering.
Also had a perfect set that looked like new, one was completely clogged at 0 cc/min flow, which is why I always send injectors in to someone to clean and balance them properly, its well-worth the money spent! Burnin' up a cylinder because flow is way down (and allowing the cylinder to run lean) is much more expensive to fix!!!
RC Engineering may be a bit more expensive, but they do a FANTASTIC job and make sure they all balance out to exactly what they should be!