The only people you find complaining on Bitcointalk for the most part are competitors or known trolls like Entropy, Bicknellski, etc...

To answer your question though: No there is nothing valid they bring to the table that qualifies as a scam. Just angry butt hurt trolls who can't stand the fact that all their idiotic "predictions" and false claims turned out to be lies and they are exposed for what they are. So they try to flood the threads and forum with more junk in hopes that people will forget.

If you actually did read the thread you would know.

So which is it?

I'd be more interested to hear your not-an-opinion-or-on the subject that BFL might have a shot at reopening this case.  On one hand, the address on their business license (official mailing address) is where you would think to send registered mail for service.  However, the place does have a website with an address on it.  So there's the common sense thing too...  what do the courts consider reasonable effort to contact in the legal world these days with email, internet, and google?

Spoken like an attorney.    Yes customers don't go quickly and see if you can wrangle even a little bit of your money payable on the spot from a company that is quickly looking like it will simply close up shop but come pay me some fees so that I may sue them for you.  Really?  What good attorney in their right mind would take a case on contingency that involves a company with no assets and attempt bitcoin recovery - an asset that even if it existed in the company's possession is virtually impossible to lien or to effectively recover by force.  Sure one can do it on principle but still I would personally view this advice with extreme skepticism.  
This is almost like a prisoners dilemma.  HF likely is waiting to see how many people will sign that refund form in order to see how much they have to pay out in refunds and if they can continue to stay in business BFL style.  Of course if very few people opt for the refund and instead sue then they will likely enter bankruptcy protection since it's pretty clear the claims of people wanting full BTC refunds would outweigh everything.  So for investomers it's lose lose.  Don't sign the form and you will likely get nothing or sign the form and get some money but you might be in a race with everyone else trying to get at least something from HF as well.

The sad part is all the lawyers are paid for with your money.    
It sucks to say this but realistically the smart thing to do is to rush over there and agree to whatever just to get some sort of money back on the spot.  Otherwise you are likely to get nothing or less then nothing since the fees you'll to your lawyers will be coming out of your pocket also.  You know the old joke.  When a bear is chasing two people you don't need to run faster then the bear just faster then the other guy.  Good luck to all.

Really do we need to have the refund in BTC debate every day?

What's really going on over there with the hardware? They said on the 28th they are going into production. They shipped some preproduction boards on new years eve. Now silence again. Did rev2 boards suck too?

AFAIK we don't issue them anymore.

Once negatively rated by people in the default trust list, hashfast's posts will have a red warning next to them by people using the default trust list. It should be there already, in fact— is it not?

They claimed that they wouldn't be using pre-orders to fund development, what they actually did is anyone's guess— much of the coin they'd been paid had apparently not been moved when people were investigating this a week ago.

It's certainly possible, even likely, that they spent some portion of it to cover the actual manufacturing— but we wouldn't know when. Though assuming their hardware works those costs should be amply recoverable.

::nods::

I think the key points are that they:

(1) Clearly promised full BTC refunds in the even that they didn't delivery in several venue and forum, including explicit direct communication

(2) Could easily have arranged to make full BTC refunds possible (by holding the coins or hedging against their change in value with an agreement with someone who was holding the coins). They claimed their manufacturing was paid for by investors, so the view that they'd hold the coin was completely realistic (and may be true).

(3) Sold products under terms that would have really only been attractive when secured by the expectation of refund of BTC paid in the event of default. They sold machines for BTC that produce BTC and can't practically be used for anything else, only a fool or a madman would buy such a machine without the expectation that they'd get as much or more BTC back from it.

When I purchased my hashrate estimate was that if they delivered on time my baby-jet units would lose about 10 BTC each, but since they were offering up to 4x more hashrate via MPP that would be enough to let me upgrade my mining hardware to "significantly less than 1.0 W/GH" at basically breakeven, or— if they were so late to deliver that MPP could not protect it against hashrate increases, that I'd receive a full refund of the BTC paid. It was my understanding and belief that hardware itself would be pretty profitable relative to COGS but I was willing to give up most of that profit with HF's high prices in exchange for they and their investors taking the considerable risk of delays and failures to deliver.

No read the refund policy in the pdf i linked. Under thier polcy you would get USD 5600 in a bank wire.

On day 1, August 8, they were $5,600. Shipping for me was $169.57. Total cost in BTC was 61.0864.