In our original review of the ASUS Eee Pad Transformer Prime I did the best I could do given limited testing opportunity with the platform before the NDA lifted on all the reviews. I made the commitment back then to come back with additional findings after I had spent more time with the platform. Today I'm back to make good on that promise.

Two more Eee Pad Transformer Prime samples later and here we are. Next week retailers and etailers should begin shipping the first orders of the Prime out to customers. There were a number of gaps I wasn't happy with in our original review of the Prime, and I've spent the past couple of weeks trying to fill them. Even what I'm presenting today isn't perfect, but when combined with the original review it should paint a more complete picture of the Eee Pad Transformer Prime.

And I've got video, something I had to cut out of the original review due to time constraints:

The WiFi Story

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 originally claimed that no one else had this issue but it looks like the CNet reviewer also noticed it. That sample went back to ASUS for diagnosis but I don't have the results back from the autopsy yet. A simple guess would be an antenna that wasn't properly connected, although it could just as easily have been something more complicated.

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. Apparently this issue was fixed in the retail lot, but may not have been addressed in what ASUS originally shipped us. Wait—second WiFi antenna?

It turns out that the Eee Pad Transformer Prime features WiFi antenna diversity. We've talked about antenna diversity most often with reference to the cellular chain on Apple's iPhone 4 and 4S, but here it's present on the Prime's WiFi. There are two antennas on the Transformer Prime, one located on either side of the front facing camera. In the second Transformer Prime sample, one of the two wasn't working. In my third review sample, taken from the retail lot that's on its way to vendors this week, both were fully functional. The result is peak WiFi performance that is virtually identical to the original Eee Pad Transformer.

There is no RF window on the back of the Prime where the two antennas are located. 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.