There's so little in common on these two devices it's like comparing apples to oranges.
No it isn't. The devices have many things in common. Let's analyze your comparison chart shall we?
- Temperature control max: 600F vs 580F. Pointless comparison point. Anything about 530F is stupid in temperature control mode.
- Temperature control min: 200F. Pointless. Anything below 380F yields no vapor in temperature control mode.
- Max power regular mode: 40W vs 120W. If you like power, sure why not.
- Max power temp limit mode: 40W vs 50J. Ignoring the fact that, again, joules means nothing here, and assuming it means watts... well, 10W difference... Woohoo!
- Min atomizer resistance, standard wire: 0.16 ohm vs 0.15 ohm. One hundredth of an ohm difference... Woohoo!
- Max atomizer resistance, standard wire: 2 ohm vs 3 ohm. Yeah okay, the SX350J is better. When was the last time you used an atomizer that has a resistance above 2 ohm though?
- Min atomizer resistance, temperature sensing: 0.1 ohm vs 0.05 ohm. Yep, that's a real improvement in the SXmini, to run dual nickel coils.
- Max atomizer resistance, temperature sensing: 1 ohm. Both chips are equal here, but nobody gives a shit: because a 1 ohm nickel coil wouldn't even fit inside a normal atomizer.
- Software upgradable: N/A vs yes. Yep, SXmini is better.
- Memory locations: N/A vs 10. I assume "memory locations" are presets. Yep, SXmini is better.
- Auto rotary display: N/A vs yes. SXmini is better, but I must admit I don't feel the need for it myself.
- Gravity sensor: N/A vs yes. Same as above really. Unless it means the ability to adjust things by tilting the mod: if you like that, then yes, SXmini is better. I hate that feature's guts personally.
So, aside from a few software niceties, a couple of meaningless specs, a really useful minimum resistance spec and more power, the devices are quite similar. The SXmini is better, sure, but it's not earth-shatteringly different.