Item Comparison Tool - World of Warcraft
1.48% crit is nice (especially for fire), but it's vs ~70 SP, 1.13% haste, 1.14% hit (your set isn't capped) plus power torrent, which is 500 int with ~25% uptime (125 int). Haste is about as useful for fire, because it suffers from long cast times and is largely dot-based.
So sorry, but I'm still not seeing it because of the above.
As for trinkets, I've simmed with both the sindragosa one and the Halion one, and given that the average SP is roughly the same, the sindragosa one comes out ahead because it has crit, and the proc has more synergy with combustion (bigger value of SP). The difference isn't that high, but I'd guess the halion one would be best given to warlocks or balance druids. Fire likes haste, but it likes crit too.