I did Altius 1 because I was considering buying their 10 FLs, but didn't like it. Highlight function is annoying, I did awful, was running out of time on everything. It was my 2nd FL practice test but still; I did NSFL1 not long after and got 503, felt like I actually learned something.
I would recommend NS1-4, EK1-4, AAMC scored, and AAMC unscored. Those 10 exams will give you the most representative practice and bang for your buck.