Companies will keep releasing pre-orders and people always seems to throw money at them, meaning MORE companies will keep doing the same!!
For a reputable company I'm talking PROVEN company 30 days pre-order should be maximum. EVen then i'd be hesitant, THey should NOT make people pay 100% of the order before shipping.
This I think may MAY be acceptable, 20% to hold your place, 30 days LATER shipping MUST start otherwise FULL refund, if shipping is about to start, to initiate the shipping process the next 80% must be paid.
But 3-5 months and 100% of $$$ wtf!!
Most of the mining hardware companies are start ups so the pre-order thing is capital injection which basically funds their development. Unfortunately there have been some spectacular rip offs and failures to deliver anywhere near on time that has skewed confidence in any company going with a pre-order approach. Better would be a % deposit held in escrow and released based on real milestones being met.
I'd like to buy a decent Scrypt miner but they too all seem pre-order....