I've got one like that. It's OK, but I often have to use it in combination with my regular soldering station.
It just doesn't heat up very quick and probably not hot enough.
I still prefer to use a regular soldering station (I've got an ERSA RDS80) with a hand-pump.
The one pictured is nice if you need to do big solderings like monitor stuff or f.i. Atari's power supply (AR2) boards, but I am scared to suck up soldering islands with it on game PCBs.
Bruno, what you did there we call "baking"

Indeed, either too low temperature applied too long OR not having fluxed the old solderings. ALWAYS add a little new solder first when you want to work on old solderings. Because of the age, the flux has gone from the solder, so it is very hard to get it melted. Add a bit new solder and it will run fine.
I could teach you a bit how to solder when we meet next time.
I've also been thinking about making a video, but there are a number of them already.