Prima Luna or sonic frontiers or audible illusions

I have always heard good things about Chris and sonic frontiers, but I would love to know what ya'll hear as sonic differences bw each pre. The prima is the most tempting bc of the exposed tubes. Aesthetically I just like the exposed tubes. However sound trumps looks by a large margin. Is the prima going to image and soundstage like the ai or sf? Is the sf or upgraded ai going to best my older ai? By what margin? I find it hard to believe I have already reached the dollar/cost threshold...

good call on the phono section...i don't need it. i'm a digital only guy. i know that is sacrilege, but it is what it is. a line stage only will serve me just fine. unfortunately i seem to recall reading that the modulus performed better than the linestage.

i have had good luck w/ my ai 2d, i hate to hear that others have had bad luck. it's the outboard power supply and dual mono that makes the ai appealing. similarly the prima was attractive b/c of it's dual mono configuration.

i looked at the vac preamps. not sure how the standard stacks up, but i can't afford to spend 3-4k on a used pre. 2k is the top of my budget unless there is something that will be truly earth shattering.

can anyone speak to the specific attributes of the aforementioned pre-amps? my 2d throws a big soundstage, but the imaging is a less pinpoint.

thanks for the advice.