Owned Clear OG for over a year and had the 800S for 4 years before selling it.
Clear is easily my preferred. Warmer, punchier, better dynamics and a more natural tone. Add a little 1-2db bass shelf at 200Hz and they become even better.
The 800S hates extra bass and gets muddled and distorted if you force it too much in the low end. Clearer high end and vocals but I think the tradeoff isn't worth it except for classical and Jazz music.
I went from Blessing 2 to Monarch MkII.
Overall there was a noticeable difference, but it wasn't huge. Mostly the tuning sounded better and the highs became a lot clearer due to the Tribrid design of the Monarchs since they have EST drivers for the air.
I think the biggest factor is good sounding IEMs is how many types of drivers there are and the crossovers used. If you have a double crossover to split up low/mid/highs and have 3 different drivers for the crossover zones then you will have 90% of the top end of sound.
Spending $200-$500 will most likely get you 95% of the $1000 mark and spending $1000 on IEMs will get you that little bit extra so if you're someone who wants to not miss out on anything you know you've gone beyond what's reasonable by enough that you feel confident in your audio.
The final 5% is probably how well the BAs are set up for the midrange since they don't cram 6 crossovers for each BA driver. Higher cost IEMs do this best.