Border Reiver:
Depends on if you like the period. There is an extensive historical background provided for each of the major armies (Ottoman Turks, Moldavia/Wallachia, Hungary, Serbia and Albania, etc.) a nice amount of colour photos, good sources for minis and the armies seem to reflect my understanding of the history of that area.
Warhammer Historical seems to do that well. The people that write their army books are constrained by history and what we did, and many of the troops look rather similar, but there are often army wide special rules to differentiate between forces, for instance welsh and caledonian armies are M5 to show the moblity of their foot troops, but are ususally without armour to show the relative poverty of the regions. Looking at the Vlad set, I think the regional variations in troops are definitely there, but my historical knowledge of Eastern europe is limited (I got it just cause I have an interest in Vlad Dracula)