I haven't gotten Bistan's ship but I have to say that, at least in the context of the Chimera challenge, I like Cassian's U-Wing. TL feeds Biggs protection, as does out of turn attacks (under Ackbar). So already 2 of the U-wing's 4 actions give Biggs TM (double if he scores a TL on the assist). The stealth can be nice to take the heat off of a damaged ship if Biggs taunt is down. The hard part is starring, modding and gearing 3 toons. Jyn in particular is a pain to star since shards never show. The good part is that trio has some use outside of fleet. I don't know if you can say the same for Bistan and SRF.
