I understand that Murder in Baldurs Gate covers this from a 4E perspective, but heard that the story wasn't particularly good
It was an early (pre-release) 5e adventure. I've run a modified version, for up to 6 players, so here's my thoughts:
Pro:
Loads of great information on Baldur's Gate.
Urban Adventure, something you don't see often enough.
Flexible format i.e. not overly pre-scripted (but see cons...)
Con:
Too many competing plot threads, with no real clear "best path" for players, so it's too likely they will want to try and do everything, especially when it's not clear exactly what a good choice might actually be.
Too many players (even 4) compounds this, as you're even more likely to have different people attracted to different goals / ideas on what to do, even if you try and align their goals etc at the beginning.
Lots of pieces scream "so what", from a players perspective - make sure you use pieces that provide decent meaningful choices and options for the players to actually get their PC's involved, too many sound cool but are more like the PC's are just observing stuff going on.
Other:
Monster stats and are form 5e beta, and combat stuff is very vague, so not really up to scratch for standard 5e; however this is pretty easily fixed by using your 5e MM and your gut instinct as far as decent challenges go.
The overall plot and NPC's do seem a bit random / light-weight at times, so be prepared to flesh things out, according to what's going to resonate for your group. Your best bet, is to make sure a few key NPC's are really well presented as the "shades of grey" types they are meant to be - no-one is obviously good or evil, but also don't make it a screw job where no matter what they do the PC's get shafted in the end (that's pretty much the story line, but try and avoid the pre-scripted complete fail; not sure I got that one completely right).
In summary, it wasn't as cool as I'd hoped, but I'm a big fan of flexible urban adventure... if you're going to use it, you just need to be prepared to do a fair amount of homework, and take a critical eye to what's presented... you can't just pick it up and run it as-is at the table, and expect a good result.
When I ran it, the first session was good, then it started to go a bit off the rails, so I threw in a more linear side-quest that took them out of town for a bit, then we honed in on them working for one chosen faction which was better. The best bit, IMO, was Coran the half-elf, an NPC one of the PC's took a shine to... Near the end, the PC's rallied a large group of townsfolk to march on to Parliament, just as it was about to get blown up... i.e. they walked right into the trap, so to speak, with no help from me... end result was all their common-folk died in the explosion, as did Coran and the rest of the Peers etc, leaving badly damaged PC's one of whom was especially annoyed that her lover was just blown to bits; un-scripted gold. Overall, it was a classic test for me as a DM, and my ability to think hard before each session as to what and how to present some interesting stuff, then ad-lib as the players invariably ran off in different directions.