I followed T1 more than P+. T1 plays faster while P+ likes halfcourt plays. T1 is more physical than P+. P+ is more popular because, aside from the fact it was established earlier than T1, it is the home of most players from their own "golden generation" (Lin Chih-chieh, Quincy Davis, Tseng Wen-ting, Lu Cheng-ju, Tsai Wei-tseng, Yang Chin-ming and Doug Creighton). T1, on the other hand, is the home for more players from the current generation of Taipei NT (Abasi, Artino, Morrison, Hu Long-mao, Chiang Yu-an among others).
T1 allows to field 3 world imports plus 2 Asian imports. Naturalized players are considered locals here. P+ only allows 3 foreign players.
All in all, I find T1 to be a better league than P+ due to the former's pace and the fact it is more of an open league. It's just that P+ is more popular. If Ricci signs with T1, it will definitely boost the popularity of the league. If Ricci signs with P+, the league will solidify its status as Taiwan's premier league.