I have an MX-450 but i don't like the ergonomics very much and rarely use it anymore (it's in a spare room).
I much prefer the feel and ergonomics of the MX-780 / MX780i or even better, the MX-890 models. (i have a few of each around the house). These feel more natural in the hand and i operate them by feel.
Randy URC MX-890, MX-780, MX-450, R40, MX-500, Sony XBR-55X900E, Panny TC-P55ST60, Tivo Roamio Pro & Premiere & OTA, TWC Arris DVR, Onkyo 333 AVR, Roku Express 4K, Panasonic Blu-Ray