I purchased a CP300i and I am very satisfied with the performance. I navigate mostly on rivers and lakes. The screen is bright even in sunlight, it was flush mounted and was easy to install. The shop that sold it to me actually convinced me not to by a lot more expensive Garmin, as the Horizon would suit my needs perfectly. Good product.
I have the cp300 with c-map charts.... would not buy again. The screen is failing on my unit, it getts all fuzzy and fades out. Also the c-map is junk, it gets confused with north up/track up and puts things in the wrong place. I have a pc based {seaclear} and Ipad with navionics... far superior