When IDW Comics finished up their "Dark Cybertron" storyline in 2014, they took the bold move of having Megatron, leader of the Decepticons in most iterations of the Transformers franchise since its beginnings 30 years earlier, renounce his membership with the Decepticons and become an Autobot. Needless to say, this was a controversial decision that fans debate to this day. Speaking only for myself, what I find perhaps even more impressive than IDW's decision to have Megatron become an Autobot is that he remained an Autobot all the way through to the end of that continuity several years later.
Although the Megatron toy that accompanied the Combiner Wars line in 2015 was not created to match Megatron's appearance in the IDW comics, Hasbro nonetheless decided to acknowledge this major change in the character. However, it would have been far too confusing a move for Hasbro to actually release a Megatron toy as an Autobot, so they gave fans the option of making their Megatron toy whatever faction they preferred with a small sticker set. As I'm firmly on record as avoiding stickers whenever possible (as seen by the otherwise-unused sheet at the feet of my specimen here in the picture), I did determine that this Megatron in my collection was to be an Autobot, other inconsistencies notwithstanding.
While Combiner Wars Megatron is a solid enough figure, and a worthy version of Megatron to add to any collection that needs one, the faction-swap option really is what makes this figure stand out from all the other Megatron figures made over the years. There are many other versions that turn into tanks by now, many other figures that more or less capture the character's essential look from G1, and many other figures that have greater articulation. If the faction-swap option doesn't mean much to you, I'm afraid I don't have too much else to say that should make you want to pick this version up rather than any of the others. But for its unusual place in Transformers history, I really do think Combiner Wars Megatron deserves highlighting.