see whether u wanna try leak rom or the more stable rom

usually, a huge version gap means there is a major update on the android version for example 4.1.2 to 4.2.2
in this case, my guess is 6.8 is the 422 leak rom while the 5.1 is 412 rom

baseband not refer to telco freq, is it a firmware that control your phone radio(Not FM radio). u can use other countries baseband(eg UK) here in malaysia.

for updated base, since wanam rom is based on samsung official/leak rom, the updated base refer to the newer samsung rom used as his rom 'base'

First of all, when you want to flash a ROM, you need to ask yourself whether u want stability or u want to try new features. If u are looking for stability and ur current ROM does not give u any headache then u can wait for major stable release only flash. Else if u like to try new things and can live with bugs then u can always try newer version.

even both are same 4.1.2, the samsung rom which wanam are based on might have different changlog number and logically, the higher changelog means newer version and hav more bug fixed and therefore more stable but it not always the case as sometimes newer rom with higher changelog are less stable than its predecessor.
You really need to read others comment or review on that particular rom release to decide whether to flash or not


the diff btween wait and flash now is u have higher chance of getting a more stable rom in the future if u wait as newer ROM esp those leaked one have stability issues most of the time