Hank-
Nice looking project. I think your welds look fine from the context that this is a grill, not an F-16 Fighter Jet. I subscribe to the same basic school of thought you do as so far all of my welds have nothing to do with keeping something safely togther while going down the road, it's just sticking projects together.
Having said that, here are some thoughts the next time you have your welder out. (I guess I can't leave well enough alone. Please ignore this if it's something that doesn't interest you.)
I've noticed that my welds tend to look much better if I use a grinding wheel to clean things down to bare (non-rusty/non-painted) metal. I see what looks like wire-brush marks next to some of your welds, but you could try really grinding it down to shiny bare steel the next time you are working on a project. If nothing else, I've noticed that I get less smoke to breath in, and less spatter with a really clean surface.
I'm not real "hip" on how much heat should go into welds, but yours look a bit 'cold' on the front side. Try turning things up a notch and see what happens. On the flip side, you could try to just slow the wire-feed-speed down a bit, as that will inherently give more heat to the situation since you're not feeding it with so much cold wire. As I say this I could be ALL WET though because there is certainly lots of evidence of heat on the backside of your welds, which is exactly what we're looking for.
Again, all of this is just one learner to another learner. I don't know JACK about this, so please don't take it as know it all or 'high and mighty'. I imagine you and I standing there in your garage going, "Well, what do ya think?" "Uhh.. I dunno, lets turn it up hotter and see what that does next time." It seems like everytime I weld it's always different and NEVER as pretty as I'd like.
Again, great project... Thanks for sharing with us!
P.S. Nice Wheel Horse!