Glarsnot Bloodcurdle loves his trukk mobz. It’s true that they’re rather fragile once they’re out of the vehicle, and are sometimes too weak after their first rumble to do too much else. However, the ability to move 12-13″, disembark 2″, then assault 6″, gives you a threat range of 21″, and even longer on a Waaagh. Even an empty trukk has its uses too, whether harassing with a big shoota or rokkit (I usually take the former), providing cover, or speeding across the battlefield threatening to neutralize objectives. Lacking a battlewagon at present, I rarely field an all-mechanized army. However, even combined with foot-sloggers they have their uses.
Typically, in smaller games, I might field only one trukk unit–usually ‘ard boyz (to make them a little more durable), held in reserve to exploit enemy weaknesses and reinforce the ork lines as need be. Nobz and Meganobz are also usefully put in trukks, increasing the survivability (and in the latter case, mobility) of these striking forces.
I haven’t ever employed a wreckin’ ball or boarding ramp yet—I’m none too confident that my foes will present me with a suitable opportunity to use them. I never take grot riggers, armour plates, or a stikkbomb chukka. If you make your (relatively vulnerable, AV10) trukks too expensive their value declines. I do always take a red paint job and ram, however, since mobility is key to their use.
Note on the pic above: yes, those are the old trukk models—I find them more suitable for dashing around the battlefield. And yes, that’s a converted “suicide ork” in the centre, complete with bomb belt. He volunteered for the job, of course!