Staglands, no contest. POE kind of really sucks.
Why is the RTwP in Staglands better than RTwP in PoE?
Well, it's more than just the combat, it's more every aspect of gameplay that is miles ahead of POE, but here are some reasons the combat in SITS is better:
1. In SITS, your attributes matter a lot, and each point you invest gives you concrete benefits. It's not like POE where you can an irrelevant 3%. Makes it fun to min max.
2. No autoresurrection. All death is permadeath. Reload when you fail, this game is not a shitty screensaver.
3. Very interesting melee/ranged builds where you pick skills that "proc" every certain number of attacks. Rather than micromanaging, you focus on higher level tactical decisions.
4. Hard counters (not hard enough IMO, but they make a difference in combat, so again superior to POE)
5. Abstract, tactical movement similar to the IE games
6. A lot less clusterfucky (IE games still did it better, due to circles that couldn't overlap, but SITS is adequate and anytime better than POE in this regard)
7. No autoregeneration.
8. Better enemy design (for example harvesters that are only vulnerable when knocked down) that makes you change tactics.
9. Better encounter design (party versus party battles) but you do have the BG1 wilderness areas or caves with trash mobs, I think this is more prominent in the early game, I'm possibly mid game, and this aspect has diminished.
10. Better loot and itemization. There is not much of it (think BG1 levels of magic items strewn around the place) and it's low key, but the concepts are solid, and the effects interesting, and there's interplay with different builds. For example, there's a magical chain whip that gives an additional bonus (can knock down enemies or something) if you have a particular skill. There are also wands that boost the effects of particular spells when you cast them.
11. Better implementation of weapon proficiencies (you get better as you train with a particular weapon), so you actually specialize by specializing.
12. Classless design - so you can build a fighter/mage, for example, or an arcane archer, by investing in the right abilities, spells and attributes.
13. No shitty per encounter abilities.
So yeah, that's the basic rundown, off the top of my head.