And the HS17 hardware is faster with better remote response time. Latest and greatest. I've had 99.9999999999999999999999% uptime since Aug 2017 install.HR24's probably won't be supported in the future... so take that gamble as well... The H/HR series is coming up to end of life. HS17 will be supported for the foreseeable future.
You choose and see all your recording preferences, series, to-dos from one centralized location.
Depends on your needs and preferences. I left a 3 DVR setup: HR44, HR24, HR20, and have never regretted it. Always have enough tuners and timers for a four person family with two teenagers. I have a 4TB external with 3TB constantly used.