ATTEN ST-990 vs ATTEN ST-1509

[DL90]

ST-990 is newer (this model began to be sold some months ago) but ST-1509 is compatible with different tools (including hot tweezers)

ATTEN ST-990: https://es.aliexpress.com/item/1005003980886993.html

ATTEN ST-1509: https://www.aliexpress.com/item/1005003660996623.html

Which one should I buy? Or maybe there is a better option for this budget?

[thm_w]

Interesting the ST-990 looks a bit like a Pace tip.
The 1509 is TRS.

Unless you need the tweezer option, I would get an Aixun or a T12 clone with lots of tips.

[DL90]

What does TRS mean?

I thought these ATTEN stations were better than a T12 clone, even better than an AIXUN

is AIXUN trustworthy? I've read a lot of issues in its topic

[thm_w]

Tip ring sleeve.
Low current connectors intended for audio use.

Atten will be more trustworthy than aixun sure, but, if you want that then buy a JBC or other major brand instead.