We take umbrage with Apple’s decision to place all but one of the iMac’s inputs around the rear of the system - only the SD card reader is mounted at the side, under the slot-loading DVD drive (still no Blu-ray unfortunately). It’s incredibly annoying having to either spin the iMac around, or fumble about at its rear, just to plug in a USB drive. A USB hub would of course sort this but with the iMac being all about minimalist chic, it's hardly something we'd want to do.
There’s a good range of connectivity options, at least. As ever the 3.5mm headphone output and line-in double as optical connectors (for digital audio) and sit alongside four USB ports, a FireWire 800 port, a Mini DisplayPort output and a Gigabit Ethernet jack. We still think that Apple has missed a trick by not including at least one video input on the 21.5in iMac. Ideally this would be an HDMI connection as it's the most universal connector around at the moment but even the mini DisplayPort sported by the 27in iMac would be a start.
Although there’s no exterior change to this generation of iMac, the internals have had what we think is a much needed overhaul. The 21.5in model now comes with an Intel Core i3 CPU as standard, running at 3.06GHz in the base model and upgradable to a 3.2GHz unit or a 3.6GHz Core i5 CPU. All support hyper-threading and the latter also offers Turbo Boost technology, whereby unloaded cores are clocked down and loaded ones over-clocked to improve performance in un-threaded applications.
Admittedly neither OS X or any of the programs you can run in it feel noticeably faster in day to day tasks. However, if you do need to run CPU-intensive programs (say, Final Cut) while performing other tasks the improved multi-tasking enabled by the Core i3 and i5 processors’ hyper-threading does make itself known. It's also a generally more power efficient architecture so you may save yourself a few pennies on your electricity bill.