Never tried Slazengers. Dont think I ever will with that kind of $$$
You should be able to find a 4-ball can of
the Slazenger Wimbledon (Ultra-Vis) for less than $4/can if you search online
(try Tennis Boom, for one). Not too easy to find in local shops in the US, sadly. I agree that this is one of the best balls on the market, easily the best I've ever used -- easiest to see, good feel, durable, good bounce, and very good quality control.
After the Slazengers, I'd go with the Dunlop
Gran Prix and then the Wilson
US Open. The Penn/Head
ATP ball is also very decent. The
Championship balls from Penn, Dunlop and Wilson are somewhat lower grade balls than the premium balls previously mentioned. Of the Championship balls I'd grade Dunlop the best and Wilson last.
The Penn Championship balls appear to be popular because the are relatively
cheap (under $2/can) and
feel a bit
softer than the others. However, they are not as durable as the others -- the bounce & liveliness is noticeably diminshed during the 2nd or 3rd set of use. The quality control of the Penn Champs seems to be somewhat less than the Dunlop and significantly less than the US Opens and other premium balls. It seems that nearly every can of Penn Champs has 1 substandard ball. It is usually either a cosmetic reject (which is usually tolerable) or, more often than not, that 3rd ball has a substandard bounce compared to the other 2 balls in the can.
On cold nights, the softness of the Penn Champs can be a plus. The Wilson & Dunlop Champs will feel often like rocks for quite a while. However, for moderate or warmer weather, I'd opt for the Dunlop Champs or one of the premium balls.