I hated the unhappy ending. Except for Lord Babington, who I liked a lot, and I'm glad at least that he and Esther are apparently going to be great together.
Why would Sidney be so willing to give up the woman he supposedly wanted, just to bail out his dipshit brother once again? Tom is so undeserving of such a sacrifice. He would have probably had the money for insurance if he hadn't wasted so much of it buying expensive and unnecessary jewelry for his wife.
Even if Eliza dies soon in the terrible accident I'm imagining for her, I don't think Charlotte should take him back. Stopping her carriage and raising her hopes, only to spout some platitudes to make himself feel less guilty? Sorry Sidney, I do think badly of you.
My ending is that she realizes that she's actually in love with Stringer, who becomes a famous and wealthy architect (maybe in America?), and they live happily ever after.