How Long Pips Work
That's a tricky question. They have no 'general' performance, since their characteristics have the wider parameter combination and variation range among all the rubbers. Some players never know for sure how to play against long pips players, because all those rubbers definitely don't play the same.
In general, long and thin (high aspect ratio), flexible long pips are the best for chopping. Flexible, high aspect ratio long pips will return a lot of spin, and some can be unpredictable. Wide spreaded pips (low pip density) will make the rubber more unpredictable. Rough top sheet (dead) will make it unable to produce spin, While smooth top sheet is spiny. Wide and/or shorter pips with thick sponge are best suited for an aggressive blocking & hit style.
All long pips work in one of the 3 following ways:
1 - They remove any spin from the ball: Same as anti, returning no spin balls. Anti is much better for a no-spin game as it has a lot of extra control. The 40mm has affected little the performance of this rubbers. If you stroke the ball in order to continue its spin (typical chopping an incoming topspin) some spin can be returned, but not as much as a chopping rubber.
2 - They randomize spin: Pips kink randomly (instead of bending all into the same direction) when contacting the ball, randomizing ball's spin. I have seen some players don't know how is spinning the ball when they push it. A skilled player can use this rubbers in a predictable way, doing things like changing the ball spin (instead of reversing its spin). This rubbers can be very versatile, and most can chop very well.
3 - They return spin: This are much more effective than anti for a spin-returning game. This are the rubbers of choice of choppers, since they can chop against topspin, and send heavy backspin. The 40mm and aspect ratio rule have get rid of the best and more effective chopping rubbers, but some rubbers can still chop with some degree of success.
Some additional considerations:
1 - Most chopping rubbers are often completely predictable, being this a weakness since most loopers will control-loop the rally, waiting for the chance to his big shot. You have to counterattack to get some success.
2 - Long pip rubbers of the type (2) can be somehow used as rubbers of type (1) or type (3) by a skilled player. A very good player can use unpredictable long pips in a predictable manner if he wishes. They come close to effectivity as rubbers of the type (3) if used properly for chopping, but personally I don't like to play with it.
3 - Some long pips can produce spin by themselves, being of any kind of the above mentioned. Also some long pips can't produce any spin at all, being of any kind of the above mentioned. This is another reason why players can't easily understand long pips.
4 - The aspect ratio rule intended to get rid of long pip rubbers that randomize spin (kind 2). They failed. There are still lots of unpredictable legal rubbers. As a side effect, they banned most of the best chopping rubbers (type 3) that where completely predictable.
5 - Most long pips rubbers have better control when facing spiny balls than when facing no spin balls.
6 - No long pips rubber returns all (100%) of the incoming spin. Antispin returns even much less spin than chopping long pips.
7 - The amount of spin returned by long pips can be augmented or diminished depending on the stroke the long pips player plays: If the stroke is spin continuing, helping pips to bend (chopping an incoming topspin), then the amount of spin returned is maximum: you should get heavy backspin. If the stroke is the opposite (re-looping an incoming topspin which is VERY difficult with chopping long pips), you return a lot less spin: you get no spin to slight backspin. If the player using long pips chooses to block, some spin is returned. Slight modifications when blocking can modify the amount of spin returned to some extent.
8 - Also note that if long pips can produce spin, you can re-loop against topspin and get some topspin. Long pips cannot be very spiny anyway.
9 - OX long pips are more likely to always return spin. Sponge long pips are more likely to return spin only if the stroke played was continuing incoming spin. The amount of spin returned is dependant to how the long pips player helps the pips in his bending through the strokes he plays in all cases.