First Thoughts on 'The Flash' / 'Arrow' crossover

Its very rare that you get a TV show crossover with a scale quite like this. Back in 2008, Doctor Who tried to do a successful crossover with Torchwood and The Sarah Jane Adventures, but sadly ended up being a lackluster episode and felt incredibly bloated despite being spread over two extra-long episodes. So its great to see these two now iconic TV super heroes coming together for a special two-part story dubbed 'The Flash vs Arrow'.
While both episodes were fantastic (and the best both shows have provided for quite a while, and forever in the case of The Flash), they managed to understand what made such a crossover interesting. Both shows have a very different approach, and you get to see the characters experience the best and worst of both Starling and Central City, as well as the best and worst of The Flash and Arrow.
The Flash's episode 'Flash vs Arrow' deals with how the characters in Central City react to having the Arrow turn up in their city. Joe and Harrison Wells bring up good points that the Arrow is much more violent, aggressive and a lot less heroic than the Flash, and Wells is unnerved further by the fact that the Arrow wouldn't entrust anyone at STAR Labs with his secret identity. Its the differences between both characters that makes this such an interesting story to watch. Both characters are heroes, but have very different approaches. The 'vs' in the title not only refers to Barry getting possessed by...whatever that villain's name was, but also the conflicting ideologies that both heroes have. There is an argument as to whether the Arrow is a hero, but also as to whether Barry can stay the way he is. He's only just starting out and is still finding his way, so Oliver helps him with advice and training to make Barry more aware of his faults to become a better hero, but Barry in turn helps Oliver by showing him the humanity still left inside of him. The latter is dealt with in Arrow's episode 'The Brave and the Bold', also providing an interesting flashback for once and Oliver basically leaving his humanity inside and becoming more of the hardened character he is in the present, as well as dealing with Barry's ignorance of just why Oliver is as brooding and as violent as he is - Starling City is a much darker, rougher place than Central City. In Central City, the bad guys can be given silly nicknames. In Starling City, the bad guys have to be stopped.

This is what makes the crossover work.
While there were a few unnecessary elements in both episodes, it was all there so that we could see both shows come together, and some ideas the writers just experiment with, like Laurel's blink-and-you'll-miss-it cameo and Barry's anger at Eddie (which was just there to lure him onto the streets for the fight).
The action was great, and while the mini Captain Boomerang arc wasn't as good as the show seemed to think it was, he provided a solid villain for the second part, and whatever-his-name-was provided a solid if a little dull villain in the first part (although his abilities proved to be a good way of exploring the character dynamics).
There was a lot to look at and question in these episodes, and I did get the impression that had you not seen all of Arrow and all of The Flash up to this point you would be lost at some parts. Also, why didn't Roy travel to Central City?
If I had to give both episodes a score, it would be an 8/10 for 'Flash vs Arrow' and a 9/10 for 'The Brave and the Bold'. I don't usually give individual episodes scores, but this was a great crossover and I hope this greatness is a sign of consistency to come.