Pears design looks quite good. I build a block that looks similar:
The middlepin tops are shaped and therefore they are hard to recognize on this picture.
klick here for more pictures and information (in german).
It performs great and beats my WW and Cascade Clone easily. Flow restrictivity is quite high but this is no problem because the performance does not depend on flowrates. I tested the block with one Aquarius 900i (900lph, 1.7m) and with four pumps in series that have nearly identical specs. The difference i measured was 0.5°C with my Barton 2530MHz@1.95V and 0.0°C difference with lower Voltages and clock rates.
I tried different jet sizes and again there was no difference. This Baseplate seems to work very well no matter how the water flows. I dont think you need multiple yets here a center inlet should be enough.
This block doesnt need to be build accurate. I made another one an that one performes at the same level
although it had been done very grubby.