Every time I take to the tennis court I play with tennis balls, so over the years I have acculumated many of these green fluffy things in my racket bag. On the whole I can play with any tennis ball given a bedding in period.
The TB920 tennis balls by Artengo really impressed me. On the face of it fresh out of the tube they look like any other tennis balls. They are well made which you can feel with the quality of the felt. When I first played with these balls I notice they have lots of life in them and bounced pretty well. They were all consistent and I had no bad bounces. The only thing I did notice is that the balls were quite hard and at times I felt my control was compromised as my strings did not bite into the ball as I wished. On the positive though this meant they held their pressure well but on hot days they did tend to fly off the strings a bit. Durability was pretty good they lasted a 3 sessions of doubles at the club which would be about average.
The TB930 balls are the premium Artengo tennis ball and come in a nice tin. They are very similar to the TB920 they bounce well, were always consistent in their bounce and held their pressure well. The biggest difference for me was how the ball felt on the strings and compared to other balls available they felt softer. There was a lovely soft feel to these balls and I felt I could make my racket put the ball anywhere on court. Whether its superior quality felt or rubber ( I suspect it is) these balls are on the money for comfort and control. One of the downsides to softer feel tennis balls is the durability however I did not feel the durability was that compromised with the TB930 balls.
Overall I was pleasantly surprised with these tennis balls. Both offer affordable performance and durability. I would recommend the TB930 for those that may have arm trouble but for general club play you cannot go wrong with the TB920.