I need a cheap AP for simple internet browsing and TV streaming, nothing fancy, thinking of:

Routerboard RB911G-5HPnD (2 external 5Ghz antennas, WIFI4, only 802.11n) I'll install 2 x pigtails with standard 10cm antennas

hAP ac lite (1 small internal 5Ghz antenna, WIFI5, 802.11ac) I prioritize stability over speed....I think Netflix need 2-4Mbits, right?, so doesn't need much speed.

They cost roughly the same....which would be the best solution?

What about hAP ax lite?

They cost roughly the same....which would be the best solution?

Apart from suggestions for some more modern device ... base RB911 is only a board. You need a case (list price $15), power adapter (price around $10), antenna pigtails and antennae them selves (price for all together probably around $20-$50). Which makes a notable price difference (and makes a "full" hAP ac a competitive option).

hAP AX2

The hap AC lite is $59 (official list price).

The Ax lite at the same price is a steal, but it has only 2.4 GHz radio, if only 2.4 GHz is ok, no doubt, go for it.

The hap AC costs more than the Ax2, $129.

The issues with the hap AC (lite or not) are the architecture (MIPSBE) and the (too) little amount of memory (16MB).

The Ax2 is relatively expensive (at $99 it is cheap for what it offers, but it offers way too much when compared to the OP needs), but as I see it right now is the only suitable device (5 GHz) with some "future", both in terms of capability for newer versions of RoS and of possible re-uses in other roles.

What about hAP ax lite?

Need 5Ghz

What about hAP ax lite?

Need 5Ghz

See also https://mikrotik.com/product/l11ug_5haxd, however personally I’d buy a ready to deploy device for a little extra

I'm aware it's just a board, but I have PSU, pigtails, antennas and box - so no extra cost there.
(by the way, get your pigtails and antennas from AliExpress at the 1/4 price)

I guess I should have asked:
What is best:
5Ghz, 1 chain 2dBi, 802.11ac, 433Mbit/s
vs.
5Ghz, 2 chain 6dBi, 802.11n, 300Mbit/s

I would guess the last, but maybe the ac standard is so much better, that is compensate for the much worse antenna-configuration.