Modern Vespa

I am new here and new to scooters.
I am looking at a 2012 LX 150 IE with 1100 miles for 2500.
The other is a 2015 Primavera 150 with 4000 miles for 2800.

Have only ridden an lx and liked it but it was a bit bumpy.

Any suggestions on which way to go?

Primavera is the new LX. There are some differences. Primavera has 11 inch wheels vs LX 11 Front and 10 rear so there maybe some greater tire choice for the 11 inch rear than the 10 inch of the LX
Primavera engine internal dimensions are different but that doesn't matter when you ride it.
Primavera of 2015 I believe still has a carburettor whereas the LX is fuel injected. So might start very marginally better in cold weather? I say marginally.

There are some minor styling difference.

There is very little difference in the ride quality and that can be changed with different aftermarket suspension, if you wish.

As you have surmised there is very little between them.

Buy the one you like the colour of?

EDIT: primavera is 155 cc which would make a difference if your state or neighbouring ones have laws regarding above 150 to ride on certain roads