Turbo boost is more of a processor feature, as far as I'm aware it's supported across the board.
Some of the chipset features become redundant at itx anyway. Like B85 can have 4 DIMM slots, H81 only two. At itx, even Z87 is stuck at two due to size. The most significant difference is likely to be the number of SATA 6Gbps ports, which on H81 is two by default. It shouldnt limit you really, but it would be a concern for some.
Also if you wanted 'extras' like Wifi, then this will dramatically cut your choices (to more expensive chipsets)