WiFi issue details in actual detail by a credible source
AnandTech - ASUS Eee Pad Transformer Prime Review Part II: Battery Life & More
"I'm on my third Transformer Prime. The original sample was almost completely broken when it came to wireless connectivity. I had very little range on the integrated WiFi and performance typically hovered around 0.5Mbps, sometimes reaching as high as 2Mbps. "
"ASUS overnighted me a second Transformer Prime; this one was tested at ASUS in California before making its way out to me. As I published earlier, I had issues with the second sample and any Apple wireless access points (Time Capsule or Airport Extreme). Using a Netgear AP I saw 16Mbps pretty consistently, but I could only get ~32Mbps if the tablet was at the right orientation with respect to the AP. ASUS' HQ eventually conceded that there might have been a problem with the second WiFi antenna on pre-production review samples"
"Aluminum does a fairly good job of attenuating RF signals, which contributes to worse range on WiFi than the original plastic Eee Pad Transformer. WiFi performance at the edge of reception as well as the maximum usable WiFi range are both noticeably lower than its predecessor. I'm still finalizing our tablet WiFi range tests to be able to quantify some of this stuff, but it's safe to say that if you were at the edge of WiFi coverage on the original Transformer, the Prime won't be any better."
Given your experience I am not going to roll the dice and become an early adopter on this one. Going to wait and see how it does with wifi in widely distributed units and potentially give them time to work out the kinks. Cancelling my pre-order with JR, hopefully I boosted some of the people here in the wait list.