I've been looking at getting a garmin vivoactive 4 for while and I can get a used one for $166 USD when converted from my local currency. But now I see the vivoactive 5 is out so I wonder if it'd be worth the price to go for the one with newer sensors. I do primarily strength training in the gym so I'm wondering if the 5 has any significant improvements on that front that will be worth the extra money. Has anyone who previously had the 4 upgraded to the 5 who can advise me on if the 5 is worth it?