In the last month I noticed that Slush was suffering too, from less and less blocks.
IMHO, It is mostly because big private pools like Bitfury, KNC and others are taking over. In the last two month hash rate jumped from around 350PH to somewhat 700TH, or doubled. The only manufacturer of small miners is AntMiner with S7 now. All others are gone private, including beloved Spondoolies. I don't believe AntMiner was able to produce over 70,000 S7s in the last three month. Although, it is possible but not probable.
I think, Spondoolies went private big time with its SP50; this single unit makes 0.11PH!!! 20 of these take out Bitminter whole capacity.
We will see less and less blocks hatched out of private pools. It seems that the days of private mining are over.
Last 60 days, shift pay dropped from about 0.00035btc/h/Th/s to 0.00025btc/h/Th/s
It is just sad reality for private miners.

 
Recently placed an order with HolyBitcoin for one SP35.
I must say; I've never had such pleasant business experience with any merchant.
Pre-sale talk was very informative and we covered a lot of topics before I sent the money. Merchant was very courteous and not pushy at all.
The rig was shipped promptly and packed very well.
After testing the rig I discovered some minor performance issues (although, fairness sake, he warned me about possibility of these issues). Regardless, the merchant offered me a courtesy refund for under-performing unit, which I accepted.
Friends, forget eBay. HolyBitcoin is the place to look for and buy used and new mining rigs. I will certainly come back for more when the time comes.
HolyBitcoin is very responsible, honest and very responsive seller.
Thanks.