180 gram records are about 20 or 25% heavier than normal LP releases. Ostensibly this is an indication that more care was put into the product, though over the years I've had some great lightweight pressings and poor heavy ones. Sometimes the opposite is the case along with a lot of mediocre.
Unfortunately, there are lots of things that can go wrong in LP production that affect sound quality. If nothing else, some buyers get stuck with the LPs from the end of the production run before the stamper is replaced. While some labels are better than others, I've always found vinyl a bit of a crap shoot in the quality control area.
Finally, the reason you don't see more 45s is that physics dictates a shorter play time when the speed is upped. LPs have a constrained play time to start with (and efforts to extend the time affect cutting levels and bass response) so if an artist wants a normal length album, a 45 is out of consideration.
Unfortunately, there are lots of things that can go wrong in LP production that affect sound quality. If nothing else, some buyers get stuck with the LPs from the end of the production run before the stamper is replaced. While some labels are better than others, I've always found vinyl a bit of a crap shoot in the quality control area.
Finally, the reason you don't see more 45s is that physics dictates a shorter play time when the speed is upped. LPs have a constrained play time to start with (and efforts to extend the time affect cutting levels and bass response) so if an artist wants a normal length album, a 45 is out of consideration.