Dropping flow meters to save $4/loop would be a supremely poor decision for most people. though at 20 loops you might pay for that IR thermometer, I suppose. I'd rather have the flow meters, personally. Sure would make balancing and purging easier.

Flow restriction on most brands of manifolds (I have no idea about yours, of course) doesn't seem to be a real big concern unless you're trying to exceed the flow meter rating, which usually only happens in snowmelting systems unless you are upsizing your pipes beyond 1/2" for some other reason.

Rob,
You are correct, I was pointing out that there are some options. I prefer the manifolds with the optional add on flow gauges, if ever you need to service the gauge it is easy. The gauge can removed with out disabling the whole manifold. Further if you chose not to use them at all it is an option.
Price is not a big spread.
Dan

Thanks again for all the input and great advice here...next question.

My building will basically have 2 slabs at 2 different elevations. The "house" portion of floor is 7 inches higher than what will be the shop and the house with radiant will be poured first. My loops will be coming and going from this shop side and was just curious the prefferred method of stubbing out in such a situation. I think I should just come out there at this 7 inch higher elevation and bend up to where there will eventually be the wall seperating the house from the shop. What is used as a sleeve? and do you just bore through the form board?