The 8a is 3mm wider, 8mm taller, and 45g heavier. Perhaps that's not a huge difference, but I already consider the 4a too big. I will likely continue not upgrading as long as LineageOS and the hardware remain usable.
I switched from 4a to 8a. The weight difference is substantial and really noticable at first. I've gotten used to it now and it runs great with GrapheneOS, but it marked an end of an era of smaller, lighter phones for me.
FWIW I was on Pixel 3a until last month; bought Pixel 6 in the meantime, but it was too big and heavy to carry around, so I only used it as a "tablet", only at home.
Just updated to Pixel 8 and it fits the hand very well (including Spigen Liquid Air cover), and doesn't feel too heavy. Have a few friends who got Pixel 8 last month on sale as well and they all confirm.
> Headphone jacks in phones are (sadly) gone forever i'm afraid.
Maybe from Google phones, for now? Possibly on smaller phones. But Best Buy sells 7 models with 5g and a headphone jack. There's almost certainly more if you shop a retailer with more variety, using Best Buy because they have decent filtering.
I like the parametric search, but searching a US retailer helps me focus on phones that are reasonable to source and use in the US. I could manage when GSM was two bands in the US, and usually two bands overseas and if you wanted a really neat phone you hoped it was quad band or at least tri band, because the really neat phones that were dual band were dual band on EU frequencies... now GSM Arena inevitably points me at phones intended for use in Japan and usually have a pretty poor match up with bands I'm likely to use while remaining flexible for use on other carriers in case it becomes a hand me down and the recipient isn't on the same carrier as me.