Well, I certainly am doing good with the bard warlock build.
I just hit level 10 and am starting to farm Ravenloft for gear. I expect the RL quests will get me to level 12, and then I will go straight to Sharn and then maybe Necro 4 or Vale.
Level 20 doesn’t seem so far away now.
I did buy the Greater Tome of Learning upgrade from the shop and also a Sovereign XP potion. So the experience is flowing in, even on the lower-level stuff.
With the Bardsong on my hireling and its summon, I can mostly sit back and let them handle the aggro.
I got the Barovian Scepter from the NPC in the entrance area. With just 2 levels of Warlock, I do good damage.