The spring part of the stat should be facing the engine, I had mental issues with QH and FORD stats, one QH at 2 days old broke, and then central pin became dislodged jamming the stat open, that was really cold and in winter too.
The bets stat by a million miles I found was the WAHLER, in 88C form, I think but not sure Matt Lewis does these now, well worth paying the extra for.
As regards jap car heaters most tend to be much better than sierra heaters!!
tabetha