Depends if the watch 4 still performs well. Does it hold a full days charge still. My upgrade to 6 there was improvement in battery to the 4th and 5th. Difference in display. Less bezel meaning a slightly bigger screen. Although still the same 40mm. Screen was a lot clearer for me too. My honest opinion if I had the 4 still, I would upgrade to 7. New chip too, should help with performance. Improved sensors also.
I had the same debate... but I decided to order the GW7. I found my GW4 is lagging a little tbh and the battery wasn't the best.
I'm hoping that because I'm jumping to a newer generation watch then I'll see some improvement - besides, I really liked the look of the GW7 and also I saved a decent amount of money on it.
I have the watch 4 classic and decided to upgrade to a 7 44mm, traded in my watch 6 that got free with the s24 ultra. Getting the 7 for £160, quite pleased with that. Won't get it till August 2nd that's the bad point😁