First lets look at landspeeders.
175 req 175 power
700hp 800 with upgrade
50 power Option to upgrade heavy melta to allow them to do armor piercing damage as well
as giving them 100 more hp
Now compare their dps to heavy bolters
Now eldar equivalents
125 req 125 power
20 dps true damage
375 hp 125 shield = 500 total hp
Now compare their dps to eldar equiv of heavy bolters the dark reapers who also do true damage.
32 dps true damage
100 req 100 pow
So what I notice is that SM can buy the landspeeders and have a unit that does more damage than their heavy weapons team equivalent.
Yet when Eldar and Ork buy their skimmer they get units that do less damage than their heavy weapon team equivalent.
The only thing that we can point to as justification for this seems to be that Eldar Vyper and Ork Deffkoppta have activated abilities as well.
To me it seems right now either landspeeder is over performing, eldar and ork equiv are underperforming or both.
Now obviously SM Ork and eldar equivalent options don't have to be as strong and have the same stats as SM but if not I would think the Ork and Eldar option should at least offer some utility in their activated abilities to compensate.
Please consider either buffing eldar and Ork version damage or adding more utility to their abilities.