Disintegrators are a fine weapon, but they occupy an awkward spot. If you're taking them, you need to load up on AT elsewhere, which is sometimes difficult.
The aircraft definitely shouldn't take DCannons, though; mixing AP values is a no-no. Shatterfield is a great weapon for dumping a bunch of hits onto a horde unit, but keep the Lances for killing off any tanks/heavy infantry they have. (Monoscythe are good enough that you often don't need to pay to upgrade them; wounding on 2s against most everything is good enough.)
Flickerfield is always worth considering. Sure, it might do nothing, or you might get hit by so many shots it's irrelevant. On the other hand, it might shrug off every one of those six Oblit shots or you might ignore the one that would've made you useless when you already got hit with a Weapon Destroyed. The more vehicles you have, the more valuable it becomes. The advantage of the Field over other cover saves is that you can guarantee it- no need to give up your shooting (and the unit inside, and any possibility of disembarking) and no need to try and squeeze behind terrain (sometimes difficult with a flying stand, and there isn't always enough for six or nine hulls.)
Night Shields are more situational, but are still quite good- better than the Field in some cases. They're best when you want to go for a long-range game followed by a short-range sweep. However, keep in mind that many of the tank-killing guns are 48" range (Autocannons, Missile Launchers, and Lascannons, just to name a few), so you are still going to get hammered by armies with good shooting. Think carefully about your game plan.
Retrofire Thrusters are useful because you don't always want to sink 150pts into an HQ with specific uses. Paying 25-50pts across your entire army is a much better deal if you're looking for deployment options, but it's definitely not something I'd always take. And again, you may want to give it to just a few select units.
Shock Prow is really good and really cheap. Tank Shocking is awesome for taking/contesting objectives, and DE vehicles can Ram at some pretty ridiculous speeds. Trading your gunless Raider for their Leeman Russ or Predator is a perfectly acceptable deal. Consider them as a way to dump those last few points, not a first pick option.
Splinter Racks are amazing when combined with Carbine Trueborn (and maybe add in The Duck for laughs.)
Grisly Trophies are more useful for insuring that disembarked units stay where you need them than keeping guys in combat. Most DE are high enough Init that getting swept isn't as much of a problem for them, and you shouldn't be losing combat by a lot unless something has gone terribly wrong.