In the Javascript API (at leasst) map.getLevel() returns a relative level. For example, if your absemap contains levels 0-18 (i.e google or bing ) and you specify LODS in your map creation of levels 9-18, zooming to level 10 will return map.getLevel() = 1 (it is the second level in the map). This is very counterintinutive and does not work well for intergrating with other maps.
I would suggest map.getLevel() with optional parameter type: absolute or relative, with absolute as the default.