I have several small networks in very rural networks that have been using old Tranzeo 900 MHz equipment. Having trouble getting the old Tranzeo equipment anymore and I am looking for a new product to use to replace these and for new installs like this. These are for small private networks for monitoring applications.

I have been looking and I see that in Mikrotik/Routerboard I have a couple of options. Either the RBMetal9HPn or another RouterBoard with a Ubiquiti XR9 radio card. Has any one compared the two options and willing to share results? Any experiences good or bad with either of them. These are on remote locations being powered by 12 volt solar systems. I used another board with some UBNT SR9 radios years ago and they worked great until the board manufacturer went away and I had to start mixing boards and OS systems. This is when I went to the Tranzeo units. Now they seem to be drying up and I am having some failures and issues.

Any advice would be appreciated.

No experience with the RouterBoard/XR9 combo, but I've got a star network of nine Metal 9HPn radios - one AP and eight stations

All of the stations are all about ~600m away from the AP. Pretty light network load - about 100 kbps TX and RX through the AP
6 dBi omni antennas on every radio, with intermittent line-of-sight to the AP

The network has been working great for a year without any hardware failures
The radios have a "hood" to keep direct sun and rain off of them, but they are exposed to atmospheric changes (dew/condensation)
Note we've drilled the CAT5 opening a little bit larger so we can fit a real PG9 cable gland and fully seal the RJ45 connection - the little cable "donut" gland that's provided seemed a bit too wimpy for me

That's great to hear. I just did my first one using the metal 9's yesterday. Mine is on a 1200 acre ranch and there is 3 links using yagi antennas pointed back to a 7 dbi omni with links ranging from 1/4 to 3/4 of a mile. So far so good, but it hasn't been 24 hours yet.