Unofficial sites are common vectors for viruses or miners. Always use a reputable antivirus and download only from trusted community-vetted sources. Stability Issues:
Repacks are smaller to download but take much longer to install. While Steam might take 15 minutes to download and unpack 80 GB, a repack might take 4 hours to download a 30 GB file and another 2 hours to install it.
In a Sweetheart Repack, the "ceiling" (the best possible card) was a vintage legend. However, the "floor" (the average pack) often contained "junk wax" from the late 80s or common cards with zero resale value. The Transparency Issue
If you are selling or reviewing a curated bundle of trading cards (like Pokémon, Magic: The Gathering, or sports cards) themed as a "Sweetheart" pack: