|Not this kind of Predator.|
It is incredibly cheap though, and you can get three for 255 points (you'll recall that a vanilla Devastator squad with missiles costs 230). The downside to simply plopping three down by default is that those three tanks will account for all your heavy support choices. The Predator can also load up on lascannons, 45 points to replace the AC with twin-linked lascannons and 65 for sponsons, but piling on the las also piles on the points and quickly turns a very cheap tank into an expensive one, 170 points for maximum lascannons.
Unlike the Devastators, or even the Rifleman to an extent, the Predator is a specialist. The dakka Predator will tear big, bloody holes in lightly-armored infantry like Orks or Imperial Guard, but will struggle against power armor infantry and vehicles heavier than a transport. The LasPred is the opposite: capable against heavy infantry, a good tank buster, but lacking the volume of fire to deal with a horde. Combining the two flavors of Predator doesn't result in a well-rounded tank, but one that performs neither job well.
|Not this Predator either.|
For vanilla Marines, the choice might be a tough one. Devastators are more expensive, but can split fire by combat squading. Preds & Dreads are cheaper and all-but immune to small arms fire, but they aren't as versatile as ML Devs and are vulnerable to the one-shot kill. For Blood Angels the choice is a bit clearer. The 20 points savings that Blood Angels get on a squad of ML Devs means that you can take two squads and a Sanguinary Priest for 470 points, while the two squads alone would cost 460 for vanilla marines. That Sanguinary Priest is the key to what makes BA Devs so wonderful. When the ease of getting a good cover save for infantry is combined with the Feel No Pain aura the Sanguinary Priest puts out, the result is a solid block of firepower that can shoot at up to four targets per turn and is very durable to return fire. They'll even have Furious Charge, but if your Devastators are assaulting something has gone horribly wrong. The savings get better if you club up to plasma (540 for vanilla, 510 for BA) or las (620 vs. 590), but then you lose some of the versatility that I find so enchanting in the missile launcher.
EV dropped a comment on the last post that anticipates this paragraph a bit. For my take on Blood Hammer, I'm looking for bodies on the table. I want to have as many infantry as I can, so swapping out infantry for vehicles goes against my aims. Hopefully my Devs can cover my approaching assault squads long enough for them to get into melta/assault range. They've done pretty well in that role, providing I actually advance with my assault squads. While I'd like the mobility that vehicles bring, to say nothing of the point savings, ultimately I don't think it's worth the trade. My missile launcher Devastators have been tearing things up and generally putting the assault squads to shame, so while I may swap them out for a different feel, I doubt I would change my list for competitive play.
Now, three days later, you know why I love Devastators.