The W5000 I had here (and the Sim2 D60 clone I recently had here) was worse off for contrast. I only measured the Sim2 D60 in at 800:1 native contrast and a little over 2500:1 dynamic contrast. I don't think I measured the W5000 when I had it here, but based off of memory, I'd say the W5000 looked subjectively the same regarding contrast. The DC2 DMD used in these models was not good. Also, the DMD chamber was not treated with an anodized black light absorptive coating like we see in the PD8150. Heavy light scatter and the DC2 DMD doomed these units from the start. Even BenQ's W20000 (their best 1080p contrast performing .95" unit produced) only saw a little more than 1000:1 native contrast. See here
for measurements. The UHD65 is much better than the W5000, but yes, a little worse off than the PD8150. What are you measuring your PD8150 in at? The stock DC3 DMD should be getting you a little over 2000:1 native (up to 2500:1) and 12000:1 dynamic contrast. Again, I don't think there's going to be a huge difference in subjective contrast between these units. Though you could argue lens quality is a lot better on these .95" DLP DMD units, but that goes without saying as the MSRP on those units was MUCH higher at the time so they could afford a better lens. I'd venture a guess that the upcoming Vivitek HK2288 will be the closest PD8150 replacement you're going to see.
I'm guessing a better lens compared to this Optoma, a little more contrast and better HDR due to more lumen output. But it's going to cost more with an MSRP of around $5000. I don't know how well it's going to sell when you can get a JVC HDR enabled projector for the same price.