If looking at the average CPU temperature through a variety of workloads, the Core i5 3470 had an average temperature at stock speeds with the reference Intel heatsink fan of 54.7°C, a peak of 81°C, and bottomed out under idling at 31°C.
The overall system power consumption for the i5-3470 with the integrated graphics ranged from 39 to 101 Watts with an average power consumption across multiple workloads of 67 Watts for the Intel Z77 system.
From my experiences with the Intel Core i5 3470 when carrying out these benchmarks, the earlier Intel HD 2500 Linux benchmarks, and various other Intel Linux benchmarks like the recent SNA testing, the i5-3470 Ivy Bridge is a reputable upper mid-range performer. The Core i5 3470 is currently retailing for just under $200 USD while the previous-generation Core i5 2500K is slightly more expensive at around $220 USD. In most -- but not all -- of the CPU benchmarks the i5-3470 does better than the i5-2500K, although the HD 3000 graphics can beat the HD 2500 graphics in some of the OpenGL workloads on Linux. The i5-3470 Ivy Bridge does run a bit warmer than the Core i5 Sandy Bridge, but its overall system power consumption is slightly lower.
In terms of the Linux experience, as with most things Intel Linux, it's great! Assuming you're running a modern Linux distribution from this year you should be in shape for Ivy Bridge. Obviously, a newer Linux kernel will always yield the best performance, power consumption, and support (sans any outstanding regressions), especially when it comes to Intel's top-of-the-line open-source driver support. If you don't need high-end graphics and care more about open-source graphics drivers, Intel has made itself the leading choice. While Intel's Linux driver is slower than their Windows driver, the level of support they put behind their Linux driver and number of developers they have working on Linux from their Open-Source Technology Center is unmatched by any other company. Intel OTC developers also have further Linux performance improvements planned.
The Ivy Bridge CPUs with integrated graphics offer comparable performance to low and mid-range discrete GPUs, especially when comparing them to the open-source drivers offered by AMD and Nouveau (reverse-engineered NVIDIA) rather than the closed-source AMD/NVIDIA drivers. Intel's open-source Linux graphics driver also supports hardware-accelerated video decoding over VA-API (AMD has yet to expose their UVD engine in open-source or documentation concerning it) so Radeon and Nouveau are just using GPU shaders for video decode. AMD still doesn't even have working open-source support for the Radeon HD 7000 series that have been on the market since the beginning of the year. There's also no reputable power management support for any modern generations of Radeon graphics hardware when using their open-source driver.
Intel's open-source driver is also leading when it comes to being the first implementing support for new OpenGL extensions within Mesa compared to the other open-source drivers. The Intel Ivy Bridge support is sadly at OpenGL 3.1 right now and not OpenGL 4.0 like under Windows, but at least they're working in the right direction and making a bulk of the upstream improvements to Mesa. The only other blemish for the Intel Linux driver right now is no open-source support for OpenCL, but I'm told by their OTC developers that there are a few people trying out some things internally. At the end of the day, if you care about open-source Linux drivers, Intel Ivy Bridge is definitely your best bet for the coming months.