Iv no idea what effect it might have, I do know that it has both head and eye tracking and they can be used seperatly or together. ObsidianAnt mentioned in one of his videos that he uses the Tobii 4c and he seems to know the game fairly well
hopefully someone with expierience will chime in.
Iv been playing around with the settings on Opentrack in combination with TrackAR and I have to admit im really impressed, Iv cleared all the jitteryness and its tracking really smooth, absolutly great for a practically free option. might do a vid showing the results
I have used both Tobii 4c and TrackIR, now Tobii have got better with time and the new Tobii 5 seems to have fixed a few of the issues 4c had. Also the software and addition of the head tracking have improved quite alot from when I used it instead of TrackIR... what I found most trouble some with Tobii, is that I need to be much more static, I found myself chasing the screen, what I mean by this, I want to read something that is not centered, like how much hull does my target has, as my eyes move to where on the screen this text is, Tobii now make the screen scroll to put what I am after to be in the center of the scree, but I knew where that infor where, so I am still trying to find the text in the wrong place, so now have to look "back" towards the center of the screen, and in the beginning, I overshot the text a few times... often I managed to read it as I it scrolled by, and I could move back to follow the target again.
Also I am a notorious multiscreen user, so I had 6 monitors when I tried Tobii, 3 screeen in a super wide screen, for games etc, and 3 auxiliary monitors for entertainment, chat, browsing etc. so with plenty of chat messages, I glanced over to the chat windows and with Tobii, I always scrolled the screen, but with TrackIR I could just move my eyes quickly to get a glance...
Tobii is not bad, it is different, and if you are being used with using something like TrackIR first. you will have a learning curve to overcome some of the things you have picked up using TrackIR...
Tobii 4c had limited mounting system, it basically had one angel to mount the sensor bar, so if you screen is not in the correct position, the tracking worked badly, the mount is otherwise really nice, as you just place a metal piece, on your monitor, and then Tobii snaps on to this metal piece with magnets. What Tobii 5 seems to have done, is to add a new mounting bracket, that allows you tilt your sensorbar, which is a great addition, as I had to manually figure out to change the angle on the mounting of my sensorbar. When used on my laptop, it worked much better, as you would have at much better angle to being with here.
Tobii 4c was also sensitive to light sources, and some would interfere with the tracking, so you might have to adjust some lights in your room, they claim that the new Tobii 5 have stronger lights and should work better in various light conditions, so you do not need to play in the dark all the time...
TrackIR and similiar solutions are "simpler" and easier to get into, so that is why I recommend these over Tobii, and if you are on a budget, then Tobii is expensive...