The easiest answer is NO, the WS12 and XPD3 do not have pre-set DIM levels, so will come ON at 100% and then DIM down. If you use a automation controller (CM15A, etc) you can program the controller to DIM the light to the OFF state so it would be possible to DIM from 0 to 25%, if you turn the light OFF by dimming to "OFF" in your software..
X10 has redesigned the WS467 wall switch and one new feature is; the light will come back ON to the same level it was turned OFF at. This would work for your requirements, however I for one do not know when the WS12 and XPD3 may do through the re-design...perhaps they already have (anybody else know?).
XPD3, being a "X10 PRO" line product is supposed to go through a burn-in period as part of manufacturer final testing. The WS12 does not. Other than that they are the same, but with different marketing (X10 PRO is aimed at contractors but anyone canpurchase).