As far as LTE, if you don't want to leave your phone behind and still have connection to tower for calls and messages then just go with the BT version. I myself leave my phone behind all the time and enjoy the freedom of not carrying a phone around all the time.I was curious to see what the trade in deals are for the 6 classic 47mm. I can get it for $6/month trading in my 5 44mm. Do I need the 3mm bigger screen or slightly newer hardware? Would the battery life be about the same? Probably. My watch 5 is almost paid off so I could keep it and wait until the 7 is released which might be a while.
I think the question I have to answer is do I see myself on Android for the next 2+ years or switching to iOS in the next couple of years?
My watch 5 is working just fine. It is laggy occasionally but I don't really need to interact with it that much throughout the day.
What would I benefit from buying the watch 6 classic LTE vs BT? My 5 is only BT and I don't see the need to use LTE on a watch. Plus I'm not sure if I have to add an extra line for the LTE 6 if I get it. In that case, it's not really worth it imo.
I am happy with my 6 classic 47mm, the battery doesn't last as long as my 5 pro, but it's a smaller battery so that is to be expected. I don't experience any lag, if there is it's not noticable to me. I am happy with my decision.
Another thing to ask yourself is do you want the rotating bezel back?
Are you having to trade in your 5 to get the 6 classic. I did that and I got $250 trade in value for my 5 pro.