I observe that many people have issues with their new iPhone 6, which is to be expected unfortunately from a massive launch of brand new hardware.
I've also seen news articles and posts advising people to sell their current devices shortly before a new launch in order to recoup maximum value. I think this advice may be mistaken.
If you have a device that works and is stable, I think it makes more sense to keep the old device until the new one is confirmed to also be satisfactory and stable. I keep my old phone as a spare. If N is the current generation phone I bought, I keep my N-1 phone as a spare. N-2 generation sold or donated. Obviously this strategy may or may not be appropriate depending on individual finances.
I've also seen news articles and posts advising people to sell their current devices shortly before a new launch in order to recoup maximum value. I think this advice may be mistaken.
If you have a device that works and is stable, I think it makes more sense to keep the old device until the new one is confirmed to also be satisfactory and stable. I keep my old phone as a spare. If N is the current generation phone I bought, I keep my N-1 phone as a spare. N-2 generation sold or donated. Obviously this strategy may or may not be appropriate depending on individual finances.