I haven't read this whole thread so I may be beating a dead horse, but I've been messing with all 4 myVegas mobile apps over the past few days.
Blackjack via the bonus card collection mechanic seems to be the fastest way to earn points. The primary slot app is much slower, but does not requires constant attention with the auto-spin feature, so you could just keep it going in the background all day with a tap every few minutes.
myKonami Slots and POP! Slots seem pretty useless for earning points
I'm not sure if it's easier/harder on the facebook browser version of the games. I'm at like 7k points now and will keep going until I get to 12k for a $25 food voucher. Just does not seem like it's worth the time to me, unless someone has found a better way than me. You could potentially buy credits and bet larger to make things go faster and still come out ahead, but I'd 100% waste more money than I'd earn trying to figure that out.
Mobile Blackjack and the Facebook version are where you'll earn your keep. The others are strictly for fun, though completing mobile slot journeys is still something to attempt. Before the update it was a decent way to gain LPs on the iOS and Amazon apps (Google Play version has always been useless). As mentioned earlier, the success of the FB version weighs a bit on maxing out the daily friend multiplier to a 500% bonus. Follow the guides online as to what to play each level. I don't know them off hand, but after a certain point it's good to play that fake Angry Birds game (can't think of the name right now) at 1K per spin and just check on it for that little bonus picking round.
As to the current value of it? I know people point out that it's not as good as it once was (what is?), but man I think any non-high roller should be attached at least slightly to this game. It takes me not much time at all, doing it for both of us, and combined we've spent $56 between the two accounts, her getting the spare change for those briefcase deals and the $50-plus getting me 4 rewards. Since last March, including Borgata trips and the upcoming Vegas trip, we've redeemed:
Aria and Mirage one night room comps, Water Club room comp, $50 in comp dollars at Borgata, $100 Borgata matchplay, $60 Borgata slot play, $25 Mirage slot play, 2 tix to Zarkana, 2 tix to KA, 2 Aria Dinner buffets, 2 Aria breakfast/lunch buffets, Monte Carlo buffet for 2, two Borgata sheet sets, couple of coffees and Madam Toussads BOGO.
On the plus, but not necessarily AP side, I've heard that having the room comps can be beneficial to bigg(er) players as your play doesn't have to cover the cost of the room. In any case, the rewards I've gotten over the years have been well worth the time and money spent. Besides, I am proof of the original intent of myVegas: getting my money over to the MGM-family. I'm still a free agent, but I don't think I'd consistently visit and stay at their properties if not for myVegas. So add my comps to myVegas and Vegas life has been good.