While Grabcraft.com has a very large collection of blueprints with many categories and themes to choose from, all blueprints on it are from 2018 or older. Additionally, the instructions are hard to follow because of an unintuitive 2D & 3D viewer.
Buildguides.net doesn’t offer the amount of blueprints Grabcraft.com has, but is much easier to build with and makes use of newer Minecraft blocks, allowing you to build beautiful structures even in the latest Minecraft versions.
Additionally, new guides are uploaded frequently and the 3D viewer has useful features such as a ‘Measure Mode’, making building even easier.
In conclusion, while Grabcraft offers more blueprints, Buildguides delivers clearer instructions with modern blocks and frequent updates