I think sitetest's going in a useful direction in that my commo with Mary or Dominic is really of a different kind from my a lot (not all) of my commo with God. Sooner or later, though I think I cover the same stuff, as far as specific requests go.
St. Anthony and the car keys: it's almost always that I ask Jesus first, then Anthony, and then thank 'em both.
But there's something "surrounding" about God that I don't think/feel about individual saints. I mean if I mean to be with God intentionally, I don't often make a lot of petitions. Generally it's more a matter of just being there. Yeah, I know that's inchoate. Sorry.
Here is a treasure from Vatican 2’s Lumen Gentium that explains our companionship with the Saints beautifully
“For just as Christian communion among wayfarers brings us closer to Christ, so our companionship with the saints joins us to Christ, from Whom as from its Fountain and Head issues every grace and the very life of the people of God.(13*) It is supremely fitting, therefore, that we love those friends and coheirs of Jesus Christ, who are also our brothers and extraordinary benefactors, that we render due thanks to God for them (14*) and “suppliantly invoke them and have recourse to their prayers, their power and help in obtaining benefits from God through His Son, Jesus Christ, who is our Redeemer and Saviour.”(15*) For every genuine testimony of love shown by us to those in heaven, by its very nature tends toward and terminates in Christ who is the “crown of all saints,”(16*) and through Him, in God Who is wonderful in his saints and is magnified in them.(17*
Actually, I couldn't agree with you more that spending good time with God is a lot more than just asking for stuff. I think spending time with God also includes things like getting to know Him better through reading His word and being in the spirit of prayer of thanksgiving. Sometimes my prayer contains few if any material petitions. So, would you say you (you all) spend time with any Saints in this type of way (in the spirit of prayer of thanksgiving to the Saint)? It seems to me that many of the Marion prayers I have read on the Vatican website have that flavor.
If so, it might be a distinction in the comparison of prayer to Saints to asking a friend for prayer. I certainly will thank my friend for praying for me, but I wouldn't spend specific time with him over and over again for just that purpose.