You know what area I've found that I do hate?
Who the bloody hell designs an area that to pass through risks instakilling constantly, and has content all over the fucking place? O_o
With bigger risks, come bigger rewards. Dark Souls is full of stuff like this. For instance, the Red Tearstone Ring, arguably one of your most powerful tools in your arsenal, is found in the Valley of Drakes, an area a low-level player will have a hard time getting through without getting killed. Plus, normally, you'd have to wait a LONG time to get there, unless you got the Master Key, in which case, you can get it minutes into the game.
The ring itself, too, is a very risk-reward kind of ring, because you gain a LOT of power, but you're one hit away from getting killed, so you have to play perfectly around that limitation.
Sen's Fortress is also a bit like that. To get the Coveteous Gold Serpent ring, you need to navigate through many unnecessary areas of the Fortress, filled with many dangers, but for your troubles, you're rewarded with a ring that makes farming what gear you want easier. Many of the other treasures hidden in the fortress are that way as well.
You can go more or less straight to Iron Golem with little deviation, or you can explore the fortress and get some goodies for your troubles. 4x Demon Titanite is pretty good if you need them to upgrade, the Gold Ring is amazing for farming as well, but you can skip all that.
You're rewarded for your troubles. For me, that's good design. It's a challenging, interesting area, with a lot of rewards, but it's not UNFAIR. It's hard, but fair. All the traps have ways of being completely avoided, and even of being exploited to help you kill the Man Serpents and Serpent Mages faster.
Sen's Fortress actually reminds me a LOT of some of the earlier Tomb Raider levels, where you'd have secret areas that were pretty hard to access, with a lot of instakills, but some nice loot at the end. You felt pretty good about getting to those secret areas, and getting the loot you so rightly deserved.
I thought Dark Souls 2 by comparison lacked areas like Sen's Fortress. Only in the DLC's did we get something resembling it, although i really liked Pharro's Lockstones, which did add some depth which Dark Souls lacked with it's frustrating invisible walls. I mean, fuck hitting every wall in the game trying to find which are really there and which aren't. Fucking Ocarina of Time did it better with the Lens of Truth FFS.