I haven't tried the new stuff, but the old primaloft was pretty good. There was nothing revolutionary about it - it performed as you would expect any high quality insulation to. The wind will whip through any insulation - down, primaloft, polarfleece - whatever, if you don't have a wind blocking layer like windstopper or that wind blocking layer Cabela's offers. If you have the vest and just need wind resistance, buy a cheap breathable raincoat that packs down to pocket size and only use it when it gets windy.

For what it is worth, I am a big fan of insulated vests. Keeping the core warm keeps everything else warm.

In the past few years I've worn several garments from Sitka, Browning and Rocky that use Primaloft, and I've found it to be remarkably warm considering its light weight. You are correct that Primaloft by itself does not block the wind. Unless it's built into a garment with a windblocking outer shell, you'll need a top layer to keep the wind out.