[j-nsp] MX104 recommended Junos version?

[Josh Baird]

This page [1] shows that the recommended version is 15.1R6, but this page
[1] says 14.1R7 for the MX104.  I know the MX104's PPC RE cannot use the
SMP kernel included in 15.1, but I understand an older kernel will be
installed for these PPC devices.

I'm currently running 14.2R6.5 but I am having some problems with high CPU
sporadically that doesn't necessarily correlate to any periods of high
traffic, etc.  Every 6 hours, the RE CPU climbs until it reaches ~60%
(sometimes higher into the ~80% range) and then falls back down to ~5%.  I
never saw this behavior when we were running 13.x with the same traffic
levels.

"show chassis routing-engine" shows most of the CPU usage at this time is
used by the kernel.

"show system process extensive" shows that chassisd is the main hog.

I suppose my question is.. what Junos release appears to be the most stable
for the MX104 platform?  Not doing anything special here - a few eBGP
peers, simple routing policy, etc.

Thanks,

Josh

[1]
https://kb.juniper.net/InfoCenter/index?page=content&id=KB21476&actp=METADATA
[2] http://www.juniper.net/support/downloads/?p=mx104#sw