Teflon insulated wire is great stuff; you can't hurt it with a soldering iron. If you are used to fighting insulation melt-back with ordinary PVC hook-up wire, you'll appreciate a great and stable insulation when you try Teflon wire.
Teflon wire is usually silver plated, because the wire is rated for use at over 125°C. At high temperatures, and over time, tin plating or solder tinning can dissolve into the underlying copper wire, leaving a surface that is difficult to solder. Silver plating can withstand higher temperatures for longer periods of time than can conventional tinning.
A common complaint about Teflon wire is that it is hard to strip. The insulation is slippery. It takes me forever to get the insulation off the wire.
Another complaint is improperly stripped (nicked) stranded Teflon wire often fails at the connection point.
Teflon insulated wire is expensive, several times more expensive than ordinary PVC insulated wire.
I picked up my Teflon wire at RadioShack a billion years ago. Item #278-552. My coils are ancient; I think my container belongs in a museum. I don't think RS has the stuff anymore. The Teflon wires are ancient but very useable.