The only downsides are that the syncing process is a bit slow (when you sync from scratch or some older blockchain snapshot) and it sometimes freezes while syncing.
If you sync using an old snapshot it may take a while depending on how old your snapshot is because I believe it will try to download all the blocks it has missed. However doing a fresh sync should take about an hour or less if you have good network connectivity, which is very fast when you consider how long any other coin which is several years old will take to synchronize. I haven't synced Bitcoin in a very long time but I've read it now takes several days even with a fast connection.
Sync from scratch is much faster like from some old snapshot so I can confirm it. After 30 mins I had fully synced blockchain from scratch.