Although ABU's Space/Simple model is very thick, they are 7.4oz/pc vs the Safari/Princes's 7.7oz/pc. Slightly more weight.
For flat-out thickness, the safari are noticeably thicker when dry than the Space. I suspect the safari are heavier not due to more sap, but due to more pulp. They seem to wick a little better, and the increase in thickness seems about right for the gain in weight. 0.3oz is not a lot more sap by dry mass, but IS a lot more pulp)
TBH though, you will be extremely hard-pressed to reach capacity in either of these diapers. I've taken a space to the wall only twice, and have yet to top off a safari.