I used boson 4.82-4.84 (just updates) and selftest. I used both because I have always used self test before (CNE3-5). As for boson I loved the online tutorial and the links. That helped huge for me. Boson has better simulations, but dont get lazy and think thats all you need to know. The test is harder then the sims I paracticed on. The different versions of the Boson (1,2,3,4)I have been told and I think read here are different writers covering the same objectives from different points of view (i.e different people) Someone correct me if I am wrong. I used Boson test #1
The self test has harder guestions, a bit better test feel with timing etc. Try one the samples are free. 12 questions but you'll get the idea and if you are studying the cisco courseware - page references.
The Boson $39.95 i believe the self test $90something. I liked having 2 different approaches before I plunked bown my $125 for the test. Just my 2 cents. The trancenders have a good rep but I have never tried them.
In short, I used and needed both I feel. Oyea!! passed last week with a 898. I had poor clock management and had to rush after the sims. They are for real so... I know you hear this everywhere on this board but practice the simulators, this is NOT a book ONLY TEST If you try it that way you will fail. Seriously. I hope I helped