I watched every damn episode of Lost, and loved about 65% of it, but I'll never understand the pedestal some people put it on.
That said, this show is not remotely Lost. Sure, it focuses entire episodes on certain characters using flashbacks to flesh them out, but Buffy/Angel did that all the time before Lost was even a glimmer in any of its creators' imaginations. It's a fairly common television device these days, and that's the only major stylistic similarity I see between the two shows, so it seems like a pretty weak comparison to me that's just being made because the creators were writers on that show.
Also, plenty of current shows can be (and are) better than Lost, imo. It's silly to suggest such a thing is impossible.