I had an 04 6.0 and had only minor problems with it, ie: 4 or 5 reprograms of the EPU and some fuel mileage issues, turbo lag and tranny shift issues.  I towed with it and generally liked it but would say a deciding factor would be if you plan to keep it past the warranty period and want to "chip" it.  If not, no problem.  

FWIW, I read somewhere (don't quote me) that International is having issues with the emissions on the 6.4 and this may delay delivery of the new engine.

This is a mute point since your post indicate that you have already made the decision and bought a ew truck.

I had a 2000 7.3L and a 2003 6.0L and now a 2006 6.0L

My 2003 and 2006 are better trucks than my 2000. Yes my 2003 had a few of the engine problems. Never left me stranded on the side of the road. But did have some turbo lag and Occassionally would not sense the proper Barametric pressure and would shut down the turbo. I survived. Just became friends with the service manager at the dealer.

My 2006 has 11,000 miles on it now. I tow almost daily. 10,000-13,000 lbs. So it's working.

The 6.0L lacks some low end torque. Starting out from a stop sign or red light with a heavy load ( espcially if on any kind of uphill grade) and you'll wish you had a lower rear end gear ratio. But once you are rolling, it a pleasure to drive.

The new engines (all diesels have to meet new emissions begining Jan 1, 2007) will run on Ultra Low Sulfur. Since most gas stations don't have multiple diesel storage tanks. I'm pretty sure we will ALL be using Ultra Low Sulfur diesel fuel. I really doubt you will see stations install new storage tanks and pumps to handle both kinds of diesel. Finding the new Ultra Low Sulfur may be difficult for a few months, but before long it will be the fuel that gas station carry. We all will be paying for the higher priced Ultra Low sulfur fuel.

The new Ford 6.4 engine will have 350hp. That's a 25 hp bump from the current 325hp.  The larger displacement and sequential turbos are supposed to help with the turbo lag. But they say the engine compartment is much much more crowded and difficult to work in.

Also the new 6.4L will have a Particulate filter in the exhaust. They rumur is that one tank of anything but Ultra Low sulfur fuel will contaminate the filter and require a new filter. Regardless of fuel contamination. It's one more filter to have to service.

I wouldn't chip any of the new Ford engines.  6.0L or 6.4L  I think they are tuned to such a perfection point that messing with the programing just increases your chances of problems. If reliability is a key issue for you. Just leave them stock.

Like you I was considering a 2008 6.4L truck. I buy a new truck every 3 years. The rebates on the 2006 trucks were such that I decided not to wait.  Ford offered a double rebate to original owners of 2003/04 6.0L trucks. With that double rebate, X-plan and Commercial Upfitter rebate I got a new truck for probably $10,000 cheaper than what I think I would have had to

Ford offered the double rebates for a incentive to get the problem trucks off owners hands so those trucks are not LABELED buyback or LEMON LAW vehicles (and can be sold with out that label attached to them)and to get the owners in another one.It wasn't just a THOUGHTFUL gesture.

Ah, hounddog, spiteful as ever. Am I going to have to get my recall book back out and remind you of all the CRAP the other two manufacturers are dealing with again? Leave it alone, we all know that some of the 6.0's were crap.

Houndog, I think you need to take a chill pill instead of making your own conclusions about why.

Yes Ford recognized they had problems with the early 6.0L. But their double rebates were not to get trucks off the street and by pass a buy back. The 2003-2004 trucks that were buyback canidates have pretty much ALREADY been bought back. With the per mile mileage fee that Ford charges a buy back customer, there is not a lot of incentive to push an older 2003/04 truck through the buyback process.

The rebate Ford offered was to anybody who purchased a 2003/04 6.0L truck. Regardless of whether you still owned that vehicle. Just prove you were the original purchaser of that vehicle and you get the rebate. If you own a 2003/04 and had purchased it used, No rebate.  Only the Original owners. It had nothing to do with getting problem trucks off the street.

So Ford seems to be trying to "Scratch the Itch" to buy a new truck and to provide an incentive to buyers who their market research suggested may be cosnidering buying again. It pushes a potential buyer over the edge to buy today instead of waiting for the next model engine. If I had a really bad experience with my Ford, a $2500 rebate is not going to keep me from changing brands. But it did intice me to buy another 6.0L rather than wait for a 6.4L

It was $4,000 coupon.NOT $2500. Some keep stating THEY all have issues.TRUE but not 430 PERCENT more issues .The 06 6.0 has LESS issues then previious but STILL has issues.Now if they were to continue the 6.0 07 or 08 may really be a goodun.BUT its getting CHANGED just when it might be as GOOD as the other two.Why such a defence for a pig in a poke.Even some of the 6.0 owners on the Ford sites finally broke down and ADMIT it.

Houndog It was NOT a $4000 coupon.

They offered a standard $2500 to ANY Buyer and an Additional $2500 Rebate to any Original owner of a 2003/04 powerstroke.

I thnik I'm a little familar with this since I owned a 2003 F350 and I got the rebate announcement in the mail around the first of March and I used the additional rebate to Purchase my 2006 truck. Along with a X-Plan and Commerical Upfitter rebate. I got $6000 in rebates off the X-plan pricing. Where I messed up was that I forgot to use the coupon that Ford sends out with their Superduty brouchures. Those coupons are worth $250-$500-$750 depending on which coupon gets stuffed in your brouchure.