There is a sort of depth in Tosphot which I feel is being forgotten in even the great Litvak yeshivot like Ponovitch or the Mir. The reason is that the emphasis in in depth learning has gone in the direction of Rav Chaim of Brisk. While that in itself is worthy and great, still the effect I think is to lose sight of Tosphot.

And one thing I can definite say about Tosphot: it is hard. It is nothing like the Rambam while at least in a  superficial reading you can get the idea. And even if you learn it with the commentaries and even Rav Chaim of Brisjk, you can still get the idea more or less. That is totally different than Tosphot where the depth clear since even to get the basic idea takes tremendous work. And it is not clear how to penetrate into the depth of Tosphot anyway. Unless you have a learning partner with a genius IQ like I had for awhile in David Bronson. Or you have a rosh yeshiva like I had in Shar Yashuv, Naftali Yegear. Otherwise what can one do? The only approach that I found to be workable is to review that same Tosphot every day word for word for about 40 days in a row. Eventually with that I found the depths of Tosphot began to be revealed.