I got the Maass this morning and am asking myself "Why?"
Leningrad, Blyskawica and Shiratsuyu all have better win rates (past 2 weeks, solo). Same 3 lead the Maass in average damage, XP, kill/death and kills per battle. The eastern Europeans are faster & better gun boats with workable torps. Shira is, well, a torp monster. The Sims is more maneuverable with MUCH faster turret traverse & reloads, making it a better "jack of all trades, master of none."
Is the Z-23 worth grinding the Maass? Hmmmm, Benson and Akizuki are 2 of my favorite DDs. Tier 9? Fletcher is really hard to beat. Tier 10? Maybe the Z-52 is worth the grind to Tier 10, but Khabarovsk still dominates there (even if it isn't really a DD).
I'm not trying to be obnoxious here. Really want to know if I should keep going. The French cruiser line isn't working all that well for me - I have similar problems looking at Algerie vs. other T7 cruisers and looking up to T8-10. However, I like to be working on something...