- Do these bombs seem balanced in terms of damage?
No, they seem weak and slow compared to other bombs like Ash of Agni, Dark Briar Barrage, Electron Vortex (all 3 of which I use often), and Nitronome (which I'm trying on the test server).

- Are these bombs fun to use?
No, in their current state, they are slow and frustrating. But the new design seems like it would be fun to use if they are fixed.

I suggest making the following changes to the new shard bombs:
1. Reduce shard fuse time by 40-50% or more (yes it needs a drastic reduction).
2. Reduce initial center blast fuse time by 20-25%.
3. Reduce bomb charge time by 15-20% (based on the Very High CTR I've been testing it with).
4. Increase each shard's blast radius.

I think the new mechanics of this design offer a fun way to add more variety to the kinds of bombs we can play with. I like the color identification of the bombs by damage type, which is also pretty. The blinking colorful shards made me think of twinkling Christmas lights.

Trying to kill turrets with these test bombs seems to be more of a pain than using other kinds of bombs for the task. Rarely, if ever, did I manage to hit a turret with two shards from one bomb. That's one of the reasons to increase the radius of each shard blast. A well placed bomb should be able to hit a turret twice and deal decent damage. Maybe the shard blasts could slightly overlap each other AND the initial center blast making it possible to double-hit a turret in either of those sweet spots.

The reason for my first suggestion has been covered by many others giving feedback. Too many monsters wander out of range of the shards by the time they explode.

The only time I felt like I was getting good results with the shard bombs was in the rank 7-3 mission "Beyond the Axes of Evil". I used Mad Bomber set, one CTR trinket, Acheron, Argent Peacemaker, Deadly Crystal Bomb, Deadly Dark Matter Bomb (level 2). For this type of level I would normally use Ash of Agni (level 10 and UV CTR Low), Glacius, Acheron, and AP or Polaris (for the turrets) with Grey Feather Mantle and Volcanic Demo Helm. I had to have CTR Max and bomb damage bonus Very High along with the best bomb for each monster type in order to match what I normally get with just one bomb (AoA CTR Ultra, no damage bonus).

Requiring new characters on the test server to be taken through all those missions in order to get access to regular tier 3 areas is rather ridiculous. I had some free time and tried to blaze through the missions. I finally got access to tier 3 clockworks maybe two days after creating the character last week, but we need to be spending that time focused on testing the new content. By the time I was using the new bombs in tier 3, I was already getting sick of the game. This does not make for good testing conditions.