I don't like rear facing ones, and if you've ever been in a vehicle with some decent boost and a rear facing snorkel you'll know why; its insanely noisy and unpleasant
Did you try this car with the ram facing forwards and backwards? I find it hard to fathom that it would make much deference to the noise levels as I haven't ever read of anyone else mentioning it, might have been noisy either way. Or if it's just for high boost cars the would be irrelevant for 99% of cars that use a snorkel.
I doubt it, given your boost levels vary a huge amount
The point is, boost is controlled by the ECU, as long as the required air is available, the ram is not going to force in air any better. I read of someone who did some testing and there was a 0.25psi difference between forwards and rearwards facing at 145km/h, it may theoretically have a minute "turbo" effect on a naturally aspirated engine (probably offset by the lack of aerodynamics) but on a turbo charged engine where the boost is regulated it wouldn't make any difference.
But if you have 1ltr of air or 500ltrs of air makes a difference.
Not if all the car requires is 1ltr, as long as it isn't a limiting factor, bigger air availibility makes no differance.
My moral to the story is, buy what you like build quality and look of, as long as it supplies the required air to the engine ( I think most reputable brands would tick this box) , there will be negligable differance between them, it dosent matter if it can supplt 1000000000x more air