I've purchased over 100 items from Cyberrebate (5 different lots), I've received rebates for the first 3 lots, the remaining two are showing as received with one lot being received next month and the other more than likely the following.
I've received my rebate checks on the date they stated it would be received, so far never a problem with getting the checks.
I did run into an instance where they supposedly failed to receive 1/2 of my rebate forms. Seemed strange, however a polite letter to the customer service group had a response the next day on how I could resubmit via fax -- I told them I didn't want further hassles and I guess being a good customer they put an override on the rebate to show it received. This was all done very quickly.
It is a hassle to go through all their hoops, but it's nice to get these things totally free (I even had free shipping on 4 out of 5 of these purchases), so I guess I've really paid $4.95 for the 100+ items The WILL take their sweet time sending the check, but they are upfront and state 12-14 weeks, and they use it all.
I've found the quality to meet and many times exceed my expectations. Items are overprices, but a bigger plus for me as I get 5% rebate on my GM card. Over $5,000 charged, that's $250 credit towards my next car purchase