Not to sure on the ultimate to be honest. Arrived today so cleaned my own windows. Just feels so flimsy, alot like using an extreme.
I'm not a fan of soft bristles, I like to feel the brush scrubbing but it felt like I was mopping the windows.
It splayed weirdly, half the bristles went left half went right, leaving a gap in the middle of the brush.
The xline bristles splay forward, with the inner bristles filling in the gaps on the outer rows, I like that.
It also has far less bristles then xline, which I accept is the only to get the weight down, but I like a bit of bush

Obviously the weight is good on the ultimate but iv never had an issue with the weight of an xline.
I have an issue where the lighter the brush I use, the harder and more aggressive I seem to clean with them, quickly destroying them in the process.
Think il stick with xline, it cleans great, it splays beautifully, it can take a beating and the weight is fine.
Anyone near me want a brand new ultimate, £20 collection only (Gu11 postcode).