I can't say I would slot these sets, even with the suggestions I'm about to make, but some thoughts...
Why not go 2% Positional Defense and 1% Typed Defense? I say this, as it would seem to make the bonuses not only different than others, but it'd knock that second defense to 1% minimum, which would be nice.
Also, why not go a straight 5% on those Resistances. Want to give a little oomph to those who 4 slot a travel. Nice even 5%. It's like those 6 slot 6% Bonuses, but it's 1 less percent but 4 slotting travel powers.
Warp
2 Set) 10% Slow Resist
3 Set) 1.75% End Dicount
4 Set) 5% Psi/Toxic Resist
Seeing as how some Winter Sets have 10% Slow Resist at 2 Set Bonuses, it doesn't seem out of place and 5% Resist in the 4 Set Spot equals the others (4.5% if the 5% is just to high).
Could even switch Set 2 and 3 if needed.
All that said, if I find a build with the slots to spare, I'd feel tempted to 6 slot Infiltrate (will have to look into some Ninja Build perhaps)