Shock is stronger and very versatile. Rarely hear a bad word about it. Mine is on its way.

I have both balls. The Venom Shock is awesome. It's not really a lite oil ball for me, but your results may vary.

While I love the original Tribal, the Tribal Fire I have yet to find a use for in my bag.

The Tribal Fire has been too angular for most.  It is suppose to be the "delayed hook" piece in the Tribal/Venom line, but just hasn't had the same versatility as the Venom pieces.  The Shock, as others have said, is much more versatile and predictable.

If you are looking for a good ball for a variety of conditions, the Shock is going to be the best bet for most bowlers.  If you wand something to move to when the lanes start to transition and need some push, the Tribal Fire may be a choice.  But to be honest, I believe there has been more success in meeting that need with the Venom Panic instead.

I believe the Tribal Fire will be one of the next balls to be replaced by Motiv along with the Octane.  Those two never met expectations for most bowlers.

Well I have both the TF and VP.  I will say both balls hooked much earlier than expected.  The house I bowl most of the time is a higher friction center and lower volume and type of oil.   Our oil seems to breakdown very quickly.  For the TF the pin is right of the ring, so that is part of the reason it is rolling earlier than expected.  So with the Panic, I wanted to make sure I got some length and put the pin up above the ring finger, and that surprised me by how early that one rolled.  I am also experimenting with the finger pitches a bit, but finding the Panic to not finish as strong as I expected either.  I haven't used on a fresh shot yet, so mostly used up open play, but have been seeing a lot of weak hits.  Several pocket 8,10's and tripping some weak 5,7's....very puzzling to me for a Motiv piece.  So I have hit the surface with 4000 and high gloss polish to see if that gives me a little better look.  Have yet to try it like that though.  Not sure if this helps or not, but just wanted to throw out my feedback having both balls.

I do see a LOT of Shocks coming out lately and many are doing very well with it.  With many reporting it to be much stronger than advertised, I thought it might be too close overall to my Sting, so I opted for the Panic as a step down from the Sting.  Still a work in progress though.

I have the Shock and absolutely love that ball...to me the Shock is to MOTIV as the HYROAD is to STORM, the ball is that freaking good.

My Shock out hooks my Revolt Vengeance...

I have not seen so many people using one Motiv ball in my area, as they do the Shock. Heck, even internet/email friends seem to be using the Venom Shock in record quantities, including myself. And I have tried many of them and not found them useful until the Shock.

The Tribal Fire seems to be a ball whose coverstock overwhelms the core. For a hybrid cover, it is or appears, in general, to be a very flippy, strong ball reaction. I think you need to either be a speed dominant player, use a rougher surface or a special drilling to use the Tribal on a house shot.

If I were you and was looking for a Shock-type reaction, that handles more oil, check out the Forza.

Just got a shock but haven't used it yet,have high hopes for it.

I would go with the Venom Shock.  I see the Shock as being a ball that easily reads the lanes and provide lots of control.  I have the Tribal Fire and find it is a very skid-snap ball that will over-react on the backends.  I have had pretty good success with it but there are definitely times when it needs to be taken off the rack.  You might want to consider the Venom Panic.  It is a great piece to dial down from the Shock and for the price of any of the Venom's there are a great deal with lots of performance.