That question is a stupid one, in that it's ridiculously vague and subjective.
The question is, who can you trust at all? BFL's slow as hell, and it sucks. Then again, so is Avalon. Who else are you going to trust? KNC? Buy ASICminer gear that is priced to NEVER make ROI?
It kinda sucks that nobody seems to be able to both develop a decent ASIC, AND develop relationships of trust with their customers, but until there are more/better options out there, people don't have a whole lot of choices if they want to be in the Bitcoin mining game.
BFL and Avalon are shitty in terms of broken promises of delivery dates, so if the question is whether you trust them to deliver ON TIME, the only rational answer is HELL no.
However, if the question is whether or not you trust that they'll deliver 'some day' (2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+2 weeks+...)
Well, they've demonstrated that they have the ability to deliver quality products on a timeline somewhere beyond 'fuck you' but still well this side of 'never'...
Will it still make ROI? That's the million dollar question everybody wishes they knew the answer to. Absent a crystal ball, I'd say, 'maybe'.
We don't know what will happen with bitcoin value over the next year, so it's impossible to say whether you're better off putting that money directly into bitcoin (or some other investment), or holding your nose and placing yet another pre-order, 'shipping in 2-60 weeks'.
As badly as certain people want their fantasy of "Sonny is a criminal who is running a scam to run away with millions of dollars in pre-orders" to come true, BFL continues to deliver on products (but not on deadlines).
Personally, I think they're absolute idiots for announcing another product that hasn't even been prototyped yet. Figured they MIGHT have learned that lesson from the last go-round. But they're clearly eternal optimists of their own abilities. I'm thinking the final product will ship your hashing power in 2-3 cards, and it'll be 3-6 months late, but that's sheer speculation...
I find that the lower you set your expectations going in, the less you set yourself up for disappointment in the future.