I ask because I'm actually kinda disappointed thusfar.

I played it expecting more of a challenge, but thusfar it's not really. The initial tutorial part of the game (everything leading to New Vegas) is definitely harder cause any random crit will be enough to kill you, but afterwards it just feels like it turns the game into a traditional Fallout (FO 1 & 2) in that the moment you get Power Armor, the challenge stops. What you lack in HP, you get in damage resistance, substantially enough that it means you're often taking the exact same amount of damage you'd normally take without the mod. (Tb-51 iirc gives 25% DR and 25 DT, meaning an Anti-Material rifle for example is going to hit you for a measely ~100 damage on very hard difficulty, when it'd hit for ~200 in the base game.) The beginning also promotes more cautious playstyle as you try to avoid being shot at entirely since one crit at the start can mess you up, so fights just don't feel as exciting. There's rarely firefights, moreso you trying to get the drop on them so you never get shot at period. That also counteracts the reduced healing on stimpacks and things like Sunset Sasparilla entirely.

I dunno, guess I'm just a tad disappointed because while there may be minor increases in difficulty, it seems to sacrifice character diversity to achieve it. It turns a situation like the Brotherhood Firing Squad during Veronica's quest into something potentially absolutely suicidal (depends on what weapons they spawn with) OR the exact same difficulty as before (the DR from medium and higher armors would rip through Gatling lasers and tri-beams, for example), but overall it encourages characters try to talk their way out. It's realistic in that of course you don't wanna take on four guys in power armor with their guns raised and pointed at you, but it's also a tad disappointing from a gameplay perspective as it encourages you to approach a scenario the exact same way every time. I was also expecting the lower carry weight to discourage carrying multiple weapons, but it STILL offers enough room to carry a range of different weapons.

Thoughts on this mod? Reasons you enjoy it or don't enjoy it...?

I tried this mod and I turned it off quickly after activating it.

It was more of a pain in the ass for the sake of being a pain in the ass than it was fun IMHO. There are much better, player-made mods out there for game difficulty and realism -- Project Nevada with its immersive features and custom game difficulty options comes to mind.