I'm glad you found it helpful - happy to share some experience!

In regards to 100% vs blends, I think it really depends and varies on the brand and use case. The durability difference might perhaps be slightly overstated for most casual wearers, but I also am not super hard on my clothes in general.

If you're serious about merino, start checking out the gsm of the fabric, and the weight/oz. This should give you an idea of how dense the material actually is - there are definitely some 100% merino products out there that are very low quality compared to blends. Construction of the actual fibers can also radically impact how well an item performs. Things like drape and fit can also affect how well merino does its job.

Above all, don't consider "merino" blends that have less than 50-60% merino - the clothing won't have the performance one expects from merino.

E: forgot to mention that anything Outlier makes is truly Onebag / BIFL appropriate. I haven't tried their UFT, but their Daybreak merino t is my current fav t-shirt. I mostly gauge merino performance on how it handles sweat, smell and repeated wearings before washing. In those regards, I don't think I've noticed a difference between blends and Outlier's stuff. Not to mention that their merino is better / on par with W&P and Duckworth's 100% stuff.

As someone who has merino-ified his wardrobe and tried & owned both brands, hopefully this novel is of some help...

As far as underwear goes, W&P's merino feels more luxurious to me but experience has shown that their elastic waistbands eventually lose their structure and get the so-called bacon effect (which annoys me personally). I have a bunch of pairs from W&P; only one older pair has gotten a small hole.

I've actually tried like 10+ different companies for merino underwear and Ridge is probably my favorite of them all - their merino feels and wears well; I've not had any issues with pilling and the waistbands have not floppified or lost their structure (this is a very common problem).

As far as t-shirts go, the reverse is true for me. I previously had a Ridge Journey t-shirt (purchased in 2020) that fairly quickly got holes from simple wearing and had to be retired out of rotation. Alternatively, W&P has got to have some of the best options for merino t-shirts. They do run long & have a slight sheen, but their range of colors & the hand feel of the merino is fantastic. I don't think I'd put the merino quality of Ridge in the same tier as W&P (it's like one immediate level below); especially if you're looking at stuff like W&P's Interlock material / 100% merino.

Other t-shirt options worth checking out during Black Friday / otherwise would be: Aviator's 100% merino air dry t-shirt, Duckworth's Maverick stuff and Outlier. Aviator if you want to try 100% merino (mine has held up very well). Duckworth has an awesome MiUSA business model and a product that matches it. Outlier is probably the king of merino t-shirts with a price to match.

YMMV of course depending on your body type (availability of fits / sizing), material preferences, use case, etc. I'd maybe recommend diversifying rather than putting all your eggs in one brand's basket; try a shirt from each to see which suits you best. Lastly, be careful thinking of merino as BIFL - some items might very well be, but typically BIFL-quality wool has a price to match.

Edit: extra comments: ethical treatment of sheep may affect merino pricing (whether or not mulesing is utilized). I also wouldn't describe W&P as wildly overpriced; they are offering a different product. Duckworth and Ridge are outdoor performance -focused, W&P is casual / business casual clothing.

There are a number of solid merino companies out there these days, but I'm not sure many of them are BIFL-appropriate (YMMV).

Pendleton is a good, affordable recommendation. I'd also advise checking out Filson and Dehen 1920 for high quality, heritage-tier wool. I have a shawl sweater coat from Dehen that I've been practically living in & have received multiple compliments (on zoom & from strangers irl); goes well with business casual.

If you're just sitting & not moving all day, you may want to consider some thick wool socks & wearing a beanie / hat in between meetings.

When in doubt, supplement with a lap cat ;)