There are many topic that elaborates on this topic already if you wanna check out what other people's experience is.
The common result is that, yes, you will get a lot more exposure and subscribers/views on webtoon because obviously the reader base over there is approximately 5 or 6 times Tapastic. (Last I check the sites' visitors stat anyway)
Although there are still a few series that are successful here in Tapastic but somehow doesn't do well in Webtoon (for example, a lot of BL comics. Webtoon just doesn't favor LGTB content as much as Tapastic) So yeah I would say the audience's tastes are different too.
