Hi Jewels,
A few nights wouldn’t be nearly enough time to evaluate any new mattress. There will be a break in and an adjustment period for any new mattress or sleeping system as the mattress loses any of its “false firmness” and the cover stretches and loosens a little and your body gets used to a sleeping surface that is different from what it is used to (see post #3 here ). This would typically be a few weeks but it can be shorter or longer depending on the specifics of the person and the mattress.
I would definitely suggest that you take more time adjusting to the new mattress, and hopefully, as time moves on you’ll gradually lose more of your previous “learned alignment” and the mattress will also lose more of its “false firmness”.
Hopefully, this will be the one for you!
Phoenix