In my case, for LF SAC305 paste, I still uses my hacked oven. 900W with IR heater at 12 liter of volume space inside the oven. The IR heater however has partially exposed metal cage to reduced the direct heat. The key is the volume (not so big) so the temperature can go up faster. Up to now, this setup still better than my T-937 for high temperature lead-free as it doesn't melt my plastic connectors. And as always, never ever put the thermocouple tip hanging in the air, put it inside a through hole pad, best is the ground pin. The only drawback is the maximum size of PCB you can put in...