with minisplits, I wouldnt run them on the road... road A/C they are not.. im sure soke here will say they run theirs on the road... as for the chinese units.. yeah theres bad ones.. but again Ive got 3 Highly modified (meaning they arent used for their intended purpose... well sort of they do cool and heat my house...).. chionese units ..since 2009 and they all work fine..
mitsubishi is the defacto standard unit.. and it costs twice as much as the others.. and mitsi wants them to only be pro-installed though you cvan get them on retail now...
theres no easy way to rattle proof a mini.. other than not use it on the road..
my units have toshiba compressors.. alot of them have sanyo compressors..
my experience with failed chinese units were they were installed in areas they shouldnt have been.. ie expected to cool so much space that they ran on maxx all the time..
imnverter compressors are great, efficient, and such until you run them at full bore.. then the boards and the motors heat up and they dont last... the boards usually burn up.. the MOSFETs on the driver boards.. alot of people throw the units away when that happens.. they can be fixed..
somewhereinusa has the right idea as he has 2 of them in his bus so neither likely runs full bore for very long
onme would be fine in a short insulated bus.. id want 2 in a long insulated bus..
and using one in a non insulated bus i think asks for trouble..
the mitsubishi units are heavier duty commercial units.. they are designed to run 24/7/365 so if you plan to tax a unit hard it may be worth it to buy these pricier units.. they are no doubt good units.
all comes down to budget and whgat conditions you are running them in.