I totally disagree with 3.5 stars--no more than 2.5 stars. Jammer tends to overinflate his grades--I mean just look at the scores he gave to a lot of BSG episodes in its last two seasons and he gave Star Trek XI 3 stars when it was no more than 2.5 stars with its poor lapses in plot logic, an utterly gratuitous Spock cameo, destroying Vulcan for pure spectacle and coming across as nothing but one of a thousand plot points that just gets lost, a villian that is nothing more than a one dimensional plot device etc etc.
3.5 stars shows look like "Cabin Fever", "Theres No Place Like Home", "Through the Looking Glass", "Confirmed Dead", "Greatest Hits", "The Shape of Things to Come", "This Place is Death", "Jughead", "Dead is Dead", "The Incident", "Ab Aeterno" which was the last great episode LOST put out. This was a middling offering even if it was just a run-of-the-mill episode but for a major event like a series finale--meh.
As a season finale it would be dead last among the other five LOST had. This had no urgency, no excitement, no tension, no big event that anchored the proceedings, no satisfying wrap ups the way "The Incident" or "Theres no Place Like Home Parts I-III" did, no abundance of cool or good character moments. For a series that did action well this had some of the most pedestrian action sequences I've ever seen.
As a series finale it failed in satisfactorily wrapping up the plot/mythology that spanned the series, the battle between Jack and MIB was dull and ultimately anti-climatic. Everything seemed rushed like the writers wanted to just get it over with and provided some of the weakest and lamest ways to handle the various plot points crammed into this outing--none of the imagination and inventiveness was present as it had been in the past i.e. the Light Source, MIB etc. It was very Heroes-like in that regard--where you drag out the season thinking that if you stick with it through all the rough patches in the season all these plot pieces will go someplace interesting in the end but instead just sort of fizzles.
The only thing good about it were a *few* isolated moments i.e. Juliet/Sawyer reunion(which I would argue was THE best LOST romance not Penny/Desmond), the final scenes after Jack meets his dad and realizes they are dead and a handful of good moments will never compensate for an otherwise weak offering--the rest of the 2.5 hours was nothing more than dull padding and was one of the rare times where I found my attention wandering instead of wholly engrossed in what was unfolding.