For me, the AI could handle more oil than my OI. The cover seems to be more versitile on the AI too. The OI is awesome when your shot starts to breakdown. They can be a good one two punch though too. Both are great balls, so it's hard to chose one or the other.

You said your switching to 15, but selling your 15# stuff?? Might want to fix that.
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Cheat to win, lie to make friends

From what I know, have seen and tried, I consider the OI to be the more versatile ball, seriously, even when older, and the more durable one.
The AI is overall stronger, more aggressive, and handles OOB more oil due to the Rough Buff finish. I have seen many people having problems with the polished Activator+, being too nervous, and strangely I heard of some AI's die quietly and losing pop after less than 100 games - while many OIs I see in my club house still go strong.

IMHO, the OI is a true benchmark ball, and a shame that it is not available anymore (unless you get your hands on a Hyper Zone-S or a black/red PBA Inferno). The AI is not bad - it is a worthy successor - but the higher performance comes at a price...

You could also look into the Zone Classic (soon to be discontinued, too!) and the Vapor Zone: same covers as OI & AI, just identical asymmetrical core and with some more drilling options.
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DizzyFugu - Reporting from Germany
Team "X" website (now available in English!): http://homepage.mac.com/timlinked/
"All that we see or seem, is but a dream within a dream..." - Edgar Allen Poe

i don't an AI but i have a vapor zone with the same characteristics as the AI.  By comparison, they are pretty close.  both balls are used mostly on med-med light conditions only.  they both hit hard.  the VZ is drilled pin right and just below ring finger.  it still is a strong ball but it goes a little longer than the OI.  

 the OI is drilled pin below ring finger cg kicked out right.  right now, the OI is my go to ball because it comes in harder than the VZ due to this drilling.  i've also downgraded but from a 16 to 15's.  it was hard to find an OI brand new at a reasonable price so i settled for a used one. i still have my 16lber cause it was my first reactive ball i've ever owned.  i got the 15lb because i know what it can do.  if i ever downgrade again, most likely i would get a 14lb too.





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Inferno Bowler: "Throwing a strike when the game starts is only a minor obstacle. Throwing a strike when you really need it in the 10th frame can be a whole different beast"   Parker Bohn III

Arsenal: Scorchin Inferno / Vapor Zone / Enriched Uranium / Original Inferno / Morich Ravage  and Target Zone.