If you put the auto into 1st it locks up the MPT. However with a 50/50 split with the MPT system its like a truck in parttime 4, so it will have difficulty turning.
Theres a mod you can do to lock up the mpt with a switch, but not for on road use.
Personally I'd go for a model with VTD, which has a ~45/55 split and is a "real" planetary diff, rather than the clutch pack on MPT based models.
All foresters are MPT except for 07/08 sport models with the vtd. Some 06+ models got VDC as well, which on MPT systems means it only goes from 60/40 to 50/50 (all 09+ foresters are MPT iirc)
04xt/4eat, 16g, STI bits and bobs