As compare to other Entrance examinations UPSEE is much easier. It is easy to qualify but a bit difficult to secure a decent rank because there are many college which are participating in UPSEE are not up to the mark interms of placement and quality education. I'll suggest WBJEE because there are many participating institutes which are decent in both the terms.
Yes, you are right! WBJEE is harder than UPSEE (UPTU). But now the question paper pattern has been changed so the level has been increased a little bit, but still it is easier than WBJEE. Also, there is one advantage of UPSEE over WBJEE which is that its score is valid for 2 years, means you can get admission on previous years marks. But WBJEE score are valid for same year only (when you write the exam).