/stats returning JSON nested objects instead of array?

The endpoint without

stats

is equivalent to

tmsh list

: it dumps the configuration information. The endpoint with

stats

is

tmsh show

and shows the stat information. They are different commands hence different outputs.

Please refer to pp. 35-38 of iControl REST User Guide Version 13.1 for more information on the statistical output. For those who would like to see example outputs, see iControl REST Cookbook - Virtual Server (ltm virtual).

If you are asking why

/mgmt/tm/ltm/virtual

returns {"items":[vs1object, vs2object, ...]} while

/mgmt/tm/ltm/virtual/stats

returns {"entries":{vs1statEndpoint: {statsObject1}, vs2statEndpoint:{statsObject2}, ....}, then I imagine that's just an implementation decision, most likely due to the differences between outputs from list/show tmsh commands.