Custom Product Options Basics
We tried all of the product option apps on Shopify. This is the only app that made adding hundreds of variants to each product as painless as possible.
We have some custom items with 300-400 variants each. With this app, you can add the variants by a comma separated list. The other apps do not do this (Bold Product Options was painful).
Also, you can set it up to have the price change on the product page. The others did not.
Technical support is great as well. I had an issue where the custom product options were not displaying in the cart. Martin hopped in the store and fixed it, quickly.
This is a great app!