There is nothing to really dislike about "Original Sins" #1, but it makes almost no case for itself as essential reading. Its three stories - one each for Deathlok, the Young Avengers and Lockjaw - are of varying relation to the main event plotline, with varying implications and editorial plans going forward. Your excitement for each will depend almost entirely on how invested you are in its title character(s), because not much happens in this issue. It's great to see old favorites on the page again, but it would be even better to see them in more engaging adventures going forward.
The Deathlok story is plainly a prequel for the series coming this fall, and this transparency of purpose is both its strength and its weakness. It's clear what the creative team is trying to accomplish, and they drive the story efficiently through its short page count. Nathan Edmondson's script is subtle in its specifics; he leaves lines like "Your mission went bad" and "I saw the bodies" to hang, so that they build suspense and keep the reader curious. However, the overall construction of his plot is very obvious. The S.H.I.E.L.D agent's dialogue is so over-the-top and all-encompassing of Clay's backstory that it doesn't always feel entirely plausible. That said, I'm pretty sure the ultimate aim of this story is to get people excited for 'Deathlok" #1, and the dialogue is an effective conveyor of the central premise for that series. In addition, Mike Perkins' and Andy Troy's art is moody and obscured, with enough futuristic glinting reds to remind you that this is much a cyborg story as it is anything else.
The Young Avengers story is probably the one I was most looking forward to. Ryan North writes a pleasant story that feels like a close cousin to Gillen and McKelvie's run. It still has an air of zaniness and self-aware enthusiasm, and it's less obviously into itself. Scenes like Prodigy wanting to stay in space and Teddy flirting with a S.H.I.E.L.D agent while disguised as Agent Coulson are as warm and funny as I could have hoped. Unfortunately, the pacing of the piece as a whole is slow. It takes a while to get to the point, and the dialogue isn't quite charming enough to keep me entertained for that long. The art is also hit-or-miss. It's quite effective in portraying the Hood and his flophouse, but the talking-head scenes felt lumpy and strange. When Noh-Varr is floating in space, he looks almost dead. The colors, though, always feel quite modern.
The wordless Lockjaw story is short and charming, like its protagonist. It's easily the most random of the stories here, but it's a cute closer to the book. Do I know why it was included? Do I think it'll be important? Not at all, but it made me smile.
"Original Sins" doesn't transcend its role as the catch-all for less popular corners of the Marvel Universe, but it doesn't do any of its characters a disservice either. It's a fine enough book that gives a glimpse into how "Original Sin" will impact the out-of-spotlight MU characters, but it definitely isn't a must-buy.