I have recently installed 1.5, customized its appearance, and loaded about 10 inventory items for testing. All went OK.

I tried adding the MSRP mod, and it will not work in 1.5. It is reported to work in 1.3.9.

I would also like to add the Stock by Attribute, which is reported to work fine in 1.3.9, but not in 1.5.

These 2 modifications are important to the operation of my business.

Would it pay to step backward and install 1.3.9 until these mods are tweaked for 1.5? What functionality would I give up by stepping back to the version that supports these mods, rather than going with the 1.5 most recent release?