I have good results. I use 0603 passives (resistors and caps.) and soic chips. The hardest parts by far are leadless parts, but even those can be done if you are creative. If you still don't believe me, I'll post pictures of some of my work ;)
Again to disagree,
SMT really simplifies DIY board making. Without those pesky holes to drill, the board comes out ready to solder. As for placing pieces, if you can etch it, you can probably solder it.
I only do single-sided boards (CNC). If the circuit is too complicated for a 1 side, I send it out, but Arduino is single side compatible, so you can do a lot with one side.
Soldering SMT is not difficult - provided you have solder wick, flux, and temp control. SMT doesn't have to mean really tight pins (in the way that through hole does mean - ~.1 pin spacing)
If one could convince Eagle to use backplane for ground only (and place GRN vias) that would be sweet.
I can't get Eagle to recognize a polygon on backside as a signal, airwires in the GRD net are not satisfied by attaching to vias into a RECT on Bottom.
However; yes, eagle can be used to layout the required patterns.
You're definitely using a polygon, not a rectangle?
A rectangle doesn't work like a poly.
You absolutely should be able to make a polygon and assign it a signal name. The airwires should work fine. I do this as a matter of course. I wonder what's different? In fact, I make large polygon pours on top and bottom and assign them to gnd. every signal wire is cut out of those ground planes.
I have used Advanced PCB at 4pcb.com before for a robot (The CalPoly/Slobotics entry for the NASA Lunar Regolith Excavation Challenge). They have some good software with an extensive online and offline library with quick turnaround. I liked them especially since their software would quote you an approximate price.