Steelseries Sensei is laser and Rival is optical but I think they'll use whatever their sponsors tell them to use and its not a giant difference between the two
Ive heard optical is best too but I think its also how well the product fits together overall and just personal preference
I think you are right about the sponsors. Wouldn't look well to use a competitors product, even if it is better or more comfortable for the player. With that in mind it is another reason to admire pro level players. They can perform no matter what they are using. That consistency is something I have always lacked which is why I tend to hit a ceiling. Plus I am getting older now and my reactions are not quite as sharp.
I used to play with a pro Q4 dueller. He gave me some advice and I have pretty much tried to keep with it. He said keep things simple. Keep your ini/config changes to a minimum and try to practice on the game on default settings / config. That way, no matter where you play, you should be able to perform.
Regarding optical vs laser, I think it depends on the player. I have always been a low sens player. I find laser mice struggle at lower DPI settings, with skipping and inaccurate movement. I can see how a higher DPI laser mouse could be useful for twitch play though, which is something that appears could give the edge in CSGO based on my very limited experience. As with most things it is personal preference I guess. But the majority of players I know, be they pro level or casual prefer optical. I think the laser mouse industry has suffered with a fad sales ethos of OH MAAAIIII GAAAD it has 5 zillion DPI, its the best mouse EVAAAAAR!!! A bit like GPU's used to advertise their memory and lead consumers to believe if it has double the memory it is twice as good.
Has anyone actually ever tried using a laser mouse on even just 4000 DPI? I played with a Razer Lachesis for a while and the DPI on max setting was ridiculous. That said, I was only on a 1280x1024 res monitor, so that might have had something to do with it
I personally believe optical is the holy grail of mice. I use an EC2 Evo, and it is probably the best mouse I have ever used. It has taken a while to rework my config files for games to account for the lack of buttons compared to the MX518, but the quality of the input is great.
I don't know what you guys generally think about the Demolition mode in CSGO, but I think it is wicked

I tell you what it reminds me of - paintball. Two teams starting relatively close to a central goal and just running for it in order secure it, then mopping up. Reminds me so much of being out at a NPF ground and shooting strangers with balls of painty pain!
I spent quite a bit of time analysing my aim too. I really need to work on my accuracy in close quarters. In a lot of confrontations I would lose because basically I kept missing! Hard to believe when the enemy player is only 2 ft away, but to my shame it is true

I am going to work on my wiggle too. That side to side dance of death.
Is there a global list of players for CS:GO with stats and such? For example Tribes uses Wilderzone, which tracks all players and gives a break down of their stats.