What are the differences between the two Samsung Galaxy Tab 4 7.0" models?

I have just got a new Samsung GALAXY Tab 4 7.0" (SM-T230NU). What is the difference (or improvements) between the 'stock' SM-T230 model GALAXY Tab 4 7.0" and the 'newer' SM-T230NU, recently released for US/Canada and in EU? Are there also other NU devices? I have also seen references to the GALAXY Tab 4 10.1" as SM-T530NU. --- I have found one possible issue , with the SM-T230 *not having* multi-user mode: > The multi users setting is not available. According to the manual it should be at settings => General => Users. (My device does have multi-user capability) --- I also saw a reference to the two different models on XDA Developers : > Do make sure your tablet is a T230NU model and not just a T230 > model. --- **UPDATE: 04-Jul-2014** There are **three** variants: T230, T230NT, T230NU from: Samsung T230 | T230NT | T230NU Galaxy Tab 4 7.0 WiFi Firmwares