With Nextera technology, it is now possible to prepare literally hundreds of libraries in a day. With respect to bias, the authors state:
Comparison to conventional methods of library preparation, relying on mechanical or endonuclease fragmentation, finds that although transposase-catalyzed adaptor insertion demonstrates a slightly greater insertion bias, this has little impact at the level of genomic coverage, and is offset by large advantages with respect to speed, simplicity, and low input requirements.As described in the paper, the Nextera system is highly versatile, and can be adapted to multiple applications. These include library preparation from as little as 10 pg DNA, exome capture, PCR-free and colony PCR library preparation, and sample prep automation.
Adey, A. et al. (2010). Rapid, low-input, low-bias construction of shotgun fragment libraries by high-density in vitro transposition Genome Biology, 11 (12) DOI: 10.1186/gb-2010-11-12-r119