I've decided, after much umming and ahhhing, to try out the Mame HLSL settings on a 32" 1080p LCD monitor. Not the most authentic set up I know... but reasonably cost effective for what looks like pretty decent payback with what I see of HLSL.
*snip*
1080p monitor is fixed... has to be as cheapo a project as possible. Basically recycling stuff I have here and buy just what I need for good HLSL setup.
As someone using HLSL on a 32" 1080p monitor often, my opinion is that HLSL is nice but...scales badly on that resolution. No matter what you do there's always a tiny bit of scaling artifacts (like uneven thickness of the scanlines visible on clear and solid color areas, creating patterns) and that even if you use integer scaling, which you can't really use with all the games anyway.
Same for the shadow mask or aperture grille, you can tell no matter which settings that it's difficult not to look a bit messy with only a 1080p monitor.
Honestly in MAME the CRT-geom shader available when you use BGFX, easily looks better than HLSL (too bad BGFX is still laggy and that saving settings is massive pain)
Currently I'm using the great ViewSonic monitor in my sig (+/-200 bucks), excellent quality and performance, most importantly it can run all games at their native refresh rates because it is compatible with CRT-Emudriver and the cards that support it, which following Calamity's guide for LCDs gives me variable refresh rate on a monitor that doesn't officially support it (not FreeSync nor G-Sync branded)
BUT I'm feeling I might have had better HLSL results with the 1440p version of that same monitor.
Though if I used such resolution and wanted the benefit of GroovyMAME's lag reduction on top of HLSL 'n stuff, I believe it'd take a reasonably powerful AMD graphics card.
Sure a WQHD 2560x1440 monitor is more in the 300 bucks range these days, and there's the cost of a decent mid-range GPU too...
No intent to push you to spend more here, just a warning of what to expect of HLSL on a 1080p monitor.
Sometimes I turn every scanlines and mask options off, and only use defocus x & y settings, which basically makes HLSL a great and precise custom smoothing filter, immensely better than the usual bilinear filter, in my eyes this feels better for playing than a messy CRT simulation.