[Avicenna]

Well, IMHO the poll isn't properly designed.
You may use stats for current limit AND stats from current session. Or you may use NONE of them. That brings the options to four cases. Besides, you may use only the last xx hands.

Use current limit only : usefull if you (and opponents) play both LHE and NLHE. May be usefull if they play quite different stakes with a differen style (say LAG at NL200 but TAG at NL400 or whatever).

Use current session only : If you think that your plays differently in the afternoon or in the evening. Or if the dynamic of one table is very different from the other.

Consider Use BOTH , or Use NONE for reason above.

Use last xx hands (say 500): If your opponent improves over time maybe.