I just find a change of pace fun every now and then, CDR can be really amusing, if you go 40% cdr you will realize that you can actually save your self a lot more than you think you could. Using E to get over walls more, Q to heal more often, W to take less damage, even your ult is on a lower CD. Still included my normal Trynd build and what a lot of people build for people who want a build that works most of the time.
Also during my testing, this build does almost the same damage as my normal build, in the end it is only like a 2 item difference, but those 2 items get you very short cooldowns. If you have CDR runes and take boots instead of Reaver you dont lose out that much on items, really the only thing you miss out on is life steal, which with CDR it doesn't matter too much since you can use your Q more to heal.