Experience with lead-free synthetic solder paste?
I've tried both on different projects and stick with lead solder for hand soldering SMT and through hole projects. I've found lead-free solder is very difficult to obtain consistent joints. Lead free soldering is successful in consumer electronics because the soldering environment can be precisely maintained compared to hand soldering on a bench. You also don't need solder paste for SMT work. I've been successful using very thin .025 solder.