Is it worth paying more for higher-end calipers?

Say Ultegra vs. 105 or Tiagra

i had 105 then ultegra and now some the shimano deep drop ones think they are 105 standard maybe tiagra all pretty much of a muchness to me

Biffer with Tiagra here – nicely set up they are great.
Obviously not disc stopping power, but then again you don't need discs on a road bike 😐

Not really. Anything from Tiagra up works very well (not tried sora brakes). When the pads wear out then fit some decent replacements – something like the dura-ace cartridges or some swiss stop greens.

Main difference is weight and pads, unless you're talking super-pricey (Dura Ace, Record, Red, boutique stuff). Go for decent ones if you can afford it, if not upgrade pads on the cheaper ones when they wear out.

Get something with a cartridge pad in a metal shoe. The difference between a block such as Sora and a cartridge such as 105 is noticable. My 105 were miles better than my Sora.

Guy I rode with changed his Tektro to Ultegra and nothing changed.

I did notice a difference from buying decent pads especially in the wet and keep your rims clean.

I hate going dh on my roadbike in the wet at 30mph+ you brake and squeeze equally and still have time to think of your loved ones and whats on in the cinema…

One thing to consider if you are buying brand new calipers then new Dura Ace 7900 series and new Ultegra 6700 series are designed to run with a different cable pull to the older stuff so mixing will not give the right performance or feel.