T2 strippers will increase your yield. The drawback is that you have to watch your strippers for burnt out crystals. In general I lose about 1 every two hours of mining; this is significantly more than the 0.02% volatility that documentation suggests. In addition to being an annoyance, and making afk-mining less profitable, this means you must carry at least five of each type of crystal (including the three in your strippers) you propose to use if you don't want to risk having to warp back to base in the middle of a typical four hour mining session. If you have, say, three types of ore in your fields, then the T2 crystals will then take up 1800m3 of your cargo space, this might spoil your two cycle cargo-hold setup.

Generally I will only use T2 strippers if I intend to mine just one type of ore, and don't mind paying attention to the screen. If I intend to afk-mine, and I seldom do, and just want to mine whatever is on hand, I find T1 strippers to be more profitable due to no loss of cycles and less fuss.