Homebrew PCBs

Using the "Staples Paper/Ironing" method, what are the best 
achievable results you have gotten for a double sided board? I mean 
what are the thinest lines (in mm or mils) and space between them. 
The reason I am asking is because I just designed a double sided 
board that is pretty complicated (I use Eagle Pro) and I don't want 
to waste my time if it can't be done at home. I have done single 
sided boards before with this method and have gotten great results. 
The best I can get this particular board to route 100% is if I use 
alot of via's. If I go with a 4 layer and send it out ($$$) then its 
not that hard to route. Just trying to get some your prior 
experiences and see if I should proceed. Thanks for taking the time 
to reply.

Also when dealing with vias how do you solder them? I was thinking 
of using thin (30 guage), bare wire and solder it on both sides of 
the board. Does anyone have any better ideas?