Overall, i quite liked Beyond Cosmo, but that has more to do with the multiplayer server I was on, than the modpack itself.

Positives:

• a modpack that includes guns
• cool hud, camera effects
• has custom progression through dimensions

Negatives:

• extremely hard earlygame, to the point that if you don't miraculously find a few diamonds for a reinforcer from security craft you will not be able to progress. Your base will be constantly bombarded by smart creepers, and by that point you might as well restart. Going in blind into your first playtrough isn't really possible. With these time constraints you cant search for a good location, you have to base wherever on the mmcn server this is mitigated by having a hideout system
• the version i had the most playtime on had some duplicate ores that you couldn't use for some recipes