Nicholas
I've always felt it impossible to overstate the ability of abrasive dust to get into places where it its least wanted, most likely to cause damage and hardest to completely clean out.
That said if you have suitable collets and are confident that personal care combined with relatively low use will keep them in good condition despite the hazards of grinding use then go for it and use them. Conversely if folk don't already have collets and holder(s) it seems silly to buy a set and subject the precision components to abrasive dangers when something easily and cheaply made will do the job.
Howard
Back around 2008-2010 or thereabouts when I seriously considered building a T&C grinder or at least an endmill sharpener I probably looked at approaching 40 articles and designs from numerous sources. Around 20 were considered worthy of scanning and saving to computer files for further consideration and, if selected, printing out ready for manufacture. (I tend to write on drawings as I go so never work directly out of a magazine or book.) As I recall it the Cannon Endmill Sharpener designed by Colin Pape, published in MEW May & June 2004 got the vote for a simple end sharpener along with the Brookes for the T&C grinder. Both seemed to offer a good balance of easy build using materials I had, or could easily get, with decent functionality without excessive work. Nothing else seemed to hit the spot for me.
Don't recall any total lemon designs. Choice being a matter of balancing what it did, how much effort to make and whether I'd actually be happy to use it. The in between "more than a simple end sharpener but less than a basic T&C grinder" designs never hit the spot for me despite being perfectly capable on their own terms. YMMD.
Although I frequently recommend Howard Hall designs there is no way I'd make them for personal use. Different philosophies mean most of Howard Halls work would be "fingernails on blackboard" for me to use.
The Brookes is basically "Quorn Lite" with much simplified construction. The Bonelle is a similar device, objectively a superior and better engineered design, much closer to "full Quorn without castings", but rather more work to make. The effort needed to make a proper Quorn being, frankly, outrageous given how much its likely to be used. (Probably not at all in reality. I'd not want to shower grinding dust over all that hard work. Especially not after making a nice box too.).
I too intended to go four facet for drill sharpening taking inspiration from the Plasplugs drill setting and flip over Vee block carrier for the drill holder. Not sure where the back of that envelope went!
The Stent always seemed a sprawling design to me taking up too much bench space. Effective though it is the Worden always seemed over-driven by using punched and bent metal sheet for the main structure to keep costs under control. That pesky price / performance / how can the retailer make a profit thing again.
Clive