Maybe I don't know what I'm talking about, but if you are using an NVMe M.2 SSD you boot times shouldn't be slow. I do remember hearing in a JayzTwoCents video that Ryzen takes a long time to POST on the first boot up, but other than that I know nothing.
Yesterday found that Corsair are giving away AIO Cooler / Ryzen AM4 mount brackets FREE. Available until 31 March 2017.
https://www.overclock3d.net/news/cases_cooling/corsair_release_am4_ready_brackets_for_their_existing_aio_liquid_coolers/1
Free Coupon Code: CORSAIRAM4BR.
First you have to open an account with Corsair so that it will accept the coupon code, then fill out the form for a free bracket. I then received confirm email asking me to phone them as order on hold. I did this with Skype free and within seconds confirmed my address and it was done. They are even sending it DHL from USA to UK .free of charge Total invoice 0.00. This is great service from Corsair