A month or so ago I discovered that running Flashpoint: Depths of Manaan in SOLO mode grants two [Manaan Research Data] at the end of each FP. When we learned we would be getting a Mannan stronghold this July, I decided to start grinding this FP for the Manaan currency to purchase the Mannan plant decorations in preparation to obtain this SH.
I've since discovered there are A LOT of great benefits to grinding this FP in SOLO mode.
* Command Experience Points (CXP). I am pulling down an absurd amount of CXP for each FP. With the new Legacy perk granting an additional 25% CXP and a boost from the Cartel Market popped, I'm earning a new Command Rank almost every run (definitely every two runs). It takes me about 20 minutes to grind the FP out on a non-stealthed toon so this is tremendously helpful.
* [Manaan Research Data]. The whole reason I started grinding this FP to begin with. Completing this FP in SOLO mode grants two of this special currency. Two are what's required to purchase the decoration from the FP vendor so each run = one decoration.
* Imperial-/Repulic-themed Walker Mount Chance. Now, even running this FP in SOLO mode offers a chance to get the Imperial or Republic command walkers. I've gotten about half-a-dozen already and have been passing them out to guild members (<Imperial Wild Space Command>).
* [Selkath Solar Sculpture] Chance. Much rarer, but still possible to get in SOLO mode, is this rare, FP-specific decoration. I've gotten two already.
* Experience. I've been grinding on Level 70 toons, but I imagine if you haven't maxed your character's level yet, this would be the ideal way to go about it.
* Grade 7 Scavenging Crafting Materials. If you grind this on a toon with the Scavenging crew skill, you can get a lot of Grade 7 green CMs (Mythra and Turadium) from the droids.
* Nar Shaddaa Nightlife Tokens. Each of the three bosses drop tokens for the NS Nightlife event active all summer long! Mostly they drop Smuggler tokens but I've gotten several Kingpin ones, as well.
REMINDER: As of 5.2.2, companions sent on crew skill missions earn Influence, so be sure to send them out while you grind!
If you're not grinding this FP before the new SH comes out I highly recommend it.