but then, you ask why another offensive in metathermics - it's because it gives me different damage type/attack options (along with some AoE) and effectively supplants that damage you are saying I'm missing out on from the lower PER xbow, doesn't it? (that's how it has seemed so far in playing, when I encounter an enemy that doesn't get hurt so well by bolts, I use more thermics.) My will+int are high and thermics is pretty effective so far - add on traps and I barely take a scratch if I am smart when going into combat.
You can achieve the same just by using grenades, except they are a much cheaper than psi because:
a) you save on skillpoints, about 50 points in throwing is enough,
b) you save on stat points, because you need only 7 dexterity for grenadier,
c) flashbangs are a great aoe disabler,
d) molotovs don't require a feat to set things on fire,
e) emp grenades stun all things robotic & drain shield emitters. And later in the game plenty enemies run around with high shield emitters. And much later in the game you get to visit places crowded with hostile robots.
Effectively with grenades you exchange one damage type (cold metathermics) for
three other types (emp, bio & expedition added plasma). It's not that metathermics doesn't work. It's just that by investing in psi for your character you are overpaying, because you could get more bang for far less buck.
