This is not so much a question as a word of caution for other potential upgraders. I pulled my Apple 'coffee can' A1470...

Go to: Apple Time Capsule And all will be revealed :)

I have upgraded my 2Tb Seagate TC to a 4Tb Green WD. Works well, and not that tricky. Hardpart was twofold: 1 Getting the thing apart is not that easy.......get yourself some non scratching plastic spludgers that are STRONG. I broke off the end of one of mine getting the bottom off. 2 The foam in the bottom of the TC is designed to take SEAGATE drives. The metal folding is slightly different in the SEAGATE. To get the WD to fit snugly I had to take a sharp knife (I used a scalpel) and slice off the bits of foam that are sticking in the way of the bottom of the WD drive. Once I did that it fitted in the case as a factory fit. I am actually thinking of buying a 6Tb drive and upgrade it again. Cheers to all. PS the price from Apple of the 3Tb drive is crazy. Get yourself a refurbed 2Tb and upgrade it to 4 or 6 Tb.

Regarding upgrading a 2011 27' iMac for Handoff: I have used the BCM94360CD combo card to successfully upgrade my 2009 Mac Pro. Handoff works well. I have a spare one of these combo cards and mini pcie adapter. I have also ordered a BTooth antenna extension cable . What I do not know is if the combo card needs to get USB power from the old BTooth slot (after I removed the old card) via a separate connector cable. Anyone know this small but important fact. I did not want to pull the machine apart (again) until I knew if I need to source a mini pcie with USB power connectors and the cable to supply the power.

Here is a word of caution for other potential upgraders re using a NON seagate drive

I pulled my Apple 'coffee can' A1470 apart to find the 2Tb Seagate.

I used a 4Tb RED WD to replace it. When inserting the drive back into the drive space I noticed a difficulty in getting the rubber moldings in the bottom of where the drive goes to wrap around the new drive. The old 2Tb Seagate has a larger cutaway on the metal folding of the case. To get the WD to fit I had to take a really sharp thin blade and carefully slice away to make a bigger space for the bottom of the WD drive, on both sides, of the rubber moldings. Now the WD fitted into the chamber OK. PLUS the small wire connections I had to take off/refit are the smallest ones I have seen. I needed a torch and a small pair of forcips to be able to get them back in place. Overall, this is not a job for anybody who might have been called 'Kaptain Klutz' in the past. The new drive works well, and possibly I may be tempted to upgrade to a 6Tb next time.

David