EXAMPLE ON NETWORK -START WITH 0 AND 1, and an ERRATA regarding, published by PMI for PMBOK 5

Examiners know better this fact than us.

So generally you will not find any complexity.

Though in case you find both options without any indication of which method has to follow then you may prefer 0 start method.(till PMBOK 4)

See below errata: first time PMI published errata on PMBOK (it is errata of PMBOK -5)

http://www.pmi.org/en/PMBOK-Guide-and-Standards/Standards-PMBOK-Guide-Errata-Sheets.aspx

177           Figure 6-18--Added the following clarifying the note to the figure. This example uses the accepted convention of the project starting on day 1 for calculating calendar start and finish dates. There are other accepted conventions that may be used

ALSO CAN REFER AT PMZILLA - http://pmzilla.com/time-management-question