It's OK at killing slimes, inefficient at killing construct, and works alright against RJ. Depends on what your intentions are for the bomb and what other gear you're planning to bring, I guess.

I have a couple videos of slime clears w/ the SSB here:
http://wiki.spiralknights.com/User:Eek5/Shard_Bombs

I don't have a DDMB to test because the damage difference isn't big enough for me to craft a second bomb. I'll try to do another run at RJP w/ the SSB and record other videos at some point since the first room isn't really representative of everything RJP throws at you.

Well, here it is:

• RJP 3 Bomb Clear

The video is basically 1-bomb runs of D14 final room, D15 (all four rooms + final room), then D16 RJ.

Here are time stamps of each room in case you want to skip around:

• Start of D15 NE Room: 1m21s
• Start of D15 NW Room: 2m33s
• Start of D15 SW Room: 4m58s
• Start of D15 SE Room: 6m19s
• Start of D15 Final Room: 7m30s
• Start of D16 RJ Fight: 10m07s

I did a one bomb approach so that the bombs could be evaluated on an even ground. Doing it this way quickly exposes each bomb's weakness rather than covering it up by using other weapons.

Nitronome
+ Fastest clear up to D15 final room
+ Best are clearing mini cubes
+ Easy to snipe silkwings
+ Deals with puppy turrets quickly
- Slowest at actual boss fight
- Struggles slightly with lichen (I knock it back into the purple slime and lose it in the video)

DR
+ Safest turret sniping IMO
+ Good at clearing both slimes and construct
+ Insanely quick boss kill (fastest)
- Struggles killing/hitting silkwings
- Has issues hitting mini cubes

SSB
+ Decent at killing slimes
= Average at dealing with lumbers
= Average at dealing with combined lichen
- Doesn't kill fast enough to prevent lichen from combining
- Struggles with killing gun puppies
- Struggles killing/hitting silkwings
- Has issues hitting mini cubes

Combined run times (including boss):
DR: 7 mins 40s
Nitronome: 8 min 58s
Shocking Salt Bomb: 11 mins 21s

D14 Final room + D15 clear speed:
DR: 7m
Nitronome: 7m
SSB: 10m 10s

Keep in mind before you defend SSB being bad at killing construct that DR is also a shadow bomb and deals neutral damage to construct as well and nitronome is a "base damage" weapon dealing "neutral" damage to everything. The regular level clears took me 43% longer w/ SSB and if you throw SSB a bone and include boss kill vs nitronome it's still 26% slower despite dealing bonus+neutral damage to 99% of the enemies compared to nitronome just dealing flat base-damage. For levels with only ~4 silkwings that take penalty damage and everything else taking bonus/neutral, the SSB should be clearing WAY faster than 10mins.

As far as boss battles go, the SSB is the best bomb for RJ that isn't paywalled so if that's all you want it for then I'd get a DDMB instead since it does 10.5% more damage on shard explosions. One thing about RJ fight is that you don't benefit from planting the bomb under RJ like you would with the old RSS; you basically want to hit him with auxiliary shards so DDMB would be a better fit for the specific application. Also, the invuln phase is a bit tricky; you need to figure out where he'll stop spinning to plant bombs down at that spot. He is vulnerable for ~7s and drop->main explosion is 4.3s so after he stops spinning you can only hit him with one main payload from a bomb you drop + whatever you put down while he was spinning so fast clears require you to guess where he'll stop spinning correctly.

Hope this helps with y our decision.