That's exactly the conclusion that I finally came to David. After looking at this from all angles, and thanks very much for the advice, I am going to put my money on the paper being the problem. I mean, that's the only variable.
Every paper has a different base white, and the more expensive fiber papers can make prints that cheap RC papers just cannot match, so I am just going to buy more Adox and be done w/ it. The Ilford paper that you mentioned is very nice but I prefer the MCC110. Here in the US, Freestyle has:
25 sheets of 11x14 Adox MCC110--$77
25 sheets of 11x14 Fomabrom--$64
12x16 would see a price spread of $95 vs $79 for 25 sheets for a $16 difference.
The Adox paper will give me a good excuse to stay home and make prints rather than going out and spending money. So it actually won't cost more! I'm just rehearsing this line of thought for the wife.
On my very first print w/ the Adox, using just a test strip and no filters, I got an absolutely perfect print w/ lustrous blacks and bright whites. Tried four different negatives after that to see if it was a fluke and got the same results. By comparison the Arista RC stuff reminded me of photo lab prints w/ their grayish plastic appearance. There's a reason people pony up more money and invest more time in making fiber prints. Not sure why it took me so long to get this.
Maybe in the end it's not that much more expensive if you don't have to make multiple prints to dial it in (see wife reasoning scheme number 1 above). Here's what others say about it below. The Fomabrom does intrigue me though. The blacks are supposed to be very velvety.
http://www.freestylephoto.biz/adox-mcc-110