Anyways.
Vehicle mode


Megatron's vehicle mode is that of a Cybertronian jet / spacecraft. I'm a little burned out on this sort of "Cybertronian vehicle" alt mode after the first 2 movies gave us such incredibly lacklustre Megatron figures, but at least this one tries to do something interesting. The head being visible as it is gives me the impression of a more utilitarian alt mode; designed for convenience and functionality. After all on Cybertron there would be no reason to hide such things.
Megatron's weapon fits on top of his alt mode. its gimmick still functions in this mode, but it rather useless. The blades won't do anything unless Megatron's opponent climbs on top of him and starts punching him.
Vehicle mode fits together very nicely; it's nice and solid. The silver/grey parts at the nose can move around, but everything else is locked into place by the legs.
Transformation is simple; fairly standard Voyager level complexity. No great surprises; basically the legs fold out from the jet's underside, the arms swing out, and the rest of the jet folds in 3 to make the upper body. The way the front armour on the jet becomes Megatron's torso armour is neat though. And this fairly cool transformation inevitably leads to...
Robot Mode

Megatron is a rather imposing and commanding looking robot character in robot mode. Every visible piece of silvery grey plastic is textured to give the impression of brushed metal. It would work better with a darker grey, or with more paint apps, but it does a good job in person of getting the idea across. The plastic is hard and solid.

Megatron's back kibble isn't anywhere near as bad as Voyager Prime's is; it folds up well and from the front it give the impression of "wings".

The face sculpt is going to be a deal breaker for a lot of people. If you're a fan of the whole TFP aesthetic, you'll probably like it a lot. Personally, I fall into that camp. If you aren't a fan of the TFP look it's probable that you'll either fall in love with the head or outright hate it.
Incidentally, that last shot shows the "brushed metal" texture on the shoulder & upper arm better.
Megatron doesn't have many paint apps but the ones he does have are effective enough; the transparent purple plastic definitely works in his case, and adds a nice leve of complexity to his appearance.
Megatron's posability is a mixed bag - limited neck movement, shoulders (balljoint), below-elbow swivel, hip (balljoint), thigh swivel. His wrists can rotate inwards, and his feet can rotate (they are not on balljoints though). He has no waist joint and, oddly enough, he has NO bicep swivel. The shoulder armour is not actually attached to the upper arms; it's on a separate pair of parts that allow extra movement for the upper arms. This extra movement does mitigate the loss of the bicep swivels to quite a degree, and it is possible to get some really nice poses out of him.


Megatron's accessories are a mixed bag. His hand held blade (held in the hand, & also pegged to the forearm) is a really nice accessory. One definitely wouldn't want to get in the way of an Angry Megatron brandishing that.
On the other hand, we have his cannon/blade/whatever that is. Pushing in the back end of the cannon will swing out 2 blade halves, and light up the clear plastic; as the piece with the light rotates it catches the clear plastic in Megatron's arm and looks pretty damn nice, to be honest. The light does not, unfortunately, light the cannon up. Pity. The blade is nice enough, but the problem is that the mechanism has no lock; let go of the cannon and it swings back again. The cannon does have some nice mechanical detailing on it, though, and as a cannon it looks VERY nice. it's just a shame that the battery cover is on the outer side of it, and VERY visible.
There is one VERY good thing about these new Voyager class light-up weapons, incidentally, that only occurred to me when I was fiddling with Megatron earlier - the electronics are NOT IN THE FIGURES. This is a BRILLIANT idea as it means that the figure's articulation and playability are in no way hampered by badly implemented gimmicks, as we've seen with other TF lines.
Conclusion
Voyager Megatron is a fairly show accurate representation of his on-screen counterpart with some nice touches, beautiful texturing, and minimal (yet effective) paint applications. I have to recommend him because although there are minor problems (weapon, bicep swivel), there's far more good to say about him than there is bad.