Eh sorry, bags make me wordy 
Yes purseforum is extremely helpful and knowledgeable and I kind of use them as a resource for that, but if you're just looking for inspiration what to buy it's a harder fit.
Forgot to mention above,
-WRT lining, I personally hate unlined bags, they're a PITA to get clean properly and I just like a lining. Synthetic lining usually = cheaper, but it's the most hard-wearing and easiest to keep clean. I like a nice thick well woven cotton. You'll be hard pressed to find a good lining in those stiffer shapes though. Sometimes they're double backed leather, like Mansur Gavriel which is an improvement on suede interiors.
-Saffiano leather, it's the very fine textured miniscule cross hatch type that almost looks 'laminated' up close. It's the most hard wearing of the lot, highly stain and scratch resistant, can handle a bit of rain, etc. I'm personally not a fan of the look (it dulls the leather's natural sheen somewhat and feels a little business like) but if you need something that can handle abuse and stand the test of time that's the one to look out for.
-Eco or vegan leather is a really 'nice' name for PU. I have a really tough time paying premium prices for this but if it suits your ethics, be my guest.
-If you can, avoid black. Black is very boring and hides a lot of sins, if you're paying a bit more for a love of design it's worth venturing into other colours to make it shine a bit more, especially if you already wear a lot of black or dark colours. Navy is often a lot more exciting (especially in a brand like Marni) but tan, oxtail, olive, and a good gray all make for good versatile neutrals with a bit more added interest than black.
Ok, deducing from your picks, the ps1 is a bit of the odd one out (and I agree it's a bit boring and also a tad dated being a former it bag) it's mostly structural/minimal/geometric which is very current now. I'm not sure how long that will last tbh and I'd be inclined to spend a little bit less on one like the APC rather than VB. I'm desperate to get back to the slouchier aesthetics and less of all the chains and blingey hardware but that's just me as I look quite classic already and structured stiff bags emphasise that too much so I may be a poor judge on the trend's longevity with my wishful thinking. If it's a silhouette that suits you well and will happily carry over the next few years/decades than it's probably worth getting the nicest quality one you can find.
Emerging or less known designers to look at:
Building Block - American, architectural, geometric/minimal, difficult to source in a wide selection in the EU though.
Vanessa Seward - APC's premium brand, supposedly a bit more grown up
and slightly more classical. Sometimes there's a really nice bag in the mix but it's a limited selection usually. Also, check the APC site, they do plenty of other nice bag silhouettes that are worth a look beyond the demi-lune, including a reverse version of it like the VB.
Céline Lefébure - sits somewhere between APC and Mansur Graviel style wise, classic shapes but not distinctly old fashioned. Think Parisian staple with somewhat reasonable pricing.
desa nineteenseventytwo - Italian, highly crafted, minimal with a nod to classical silhouettes in a very contemporary way but collections vary from season to season as do the prices online (v. affordable with yoox but limited selection).
M2Malletier - Spanish, very small curated collection, more angular with precision hardware, you like it or you don't pretty much.
Yvonne Kone - Danish, more on the slouchier end but gorgeous quality (mostly buffalo leather which is very hard wearing and all handmade in Italy). The pumps are worth buying coveting too.
This article has a few great under the radar brands compiled too.
I've also semi-recently gotten sucked into tictail which is sort of a Scandi based insta/etsy mashup with a lot of independent labels. Generally a lot more affordable but have yet to buy anything from there. It's a lot easier to wade through than etsy though. It's an app but has an easy to navigate web interface too and most shops use the interface as their public webshop. Bag brands I've discovered on there so far and like the look of:
Kles (UK based)
Peet Dullaert (Netherlands)
Kuula + Jylhä (Finland)
MYR (Sweden)