That's a great question. The new project X LZ shafts are awesome. I have them in my 718 AP2 and T-MB combo and they are one of the best shafts I've ever played.

It depends on what you want out of the golf shaft. The PXi shafts are 7 grams lighter (comparing 5.5s). I think that the LZ's are the perfect blend of mid-weight and have a smoother transition. I thought the PXis were a little too light for me, as I was used to True Temper before which was about 125 grams. So going from 125 grams to 108 was a big change for me.

I have played the regular Project X, PXi, and the LZ and this is the best one yet. I'm surprised that more pros have not switched over to these, but if they are used to what they have been playing with, stick with it.

I would suggest getting fitted and give them both a try side by side. But I don't think you would be disappointed if you went with the LZ.

Thank you Samuel, that is how I have been leaning and hopefully can find a good fitting cart in my area. At times the PXi 5.5 does feel a little whippy and at times I can get squirrelly when I have a quick down swing tempo. I think the slightly heavier LZ 5.5 compared to the PXi 5.5 might be helpful in that situation. The heavier weight may also slow down my swing a little and help keep my head down. (at least that is what I hope for)