The PWT definitely was much tougher. I would challenge the place with Emboar, Jellicent, Flygon, Tangrowth, Eelektross, and Lucario. The most I think I just reached the champions. If not, then I am close to beating the gym leader sets.  But honestly, this is surely a challenge. It is great that I am able to use my own pokemon, but the ones the PWT supplies are super, super tough to beat. Their stats are jacked up really high. A super effective hit from them 1-hit ko's me. while a super effective move I send at them only does half. The only gym leaders I am sure to beat are ground, grass, and electric, since Flygon and Eelektross have levitate, and Emboar can use Earthquake. Also, Jellicent has a quick claw and water spout, so does 4x damage to pokemon like Golem. The only time i win a tournament is when I have easy leaders.... Dragon type gym leaders are impossible to beat since their pokemon have higher stats that other PWT pokemon, which are already powerful...

The battle frontier might not have the easiest ways to battle the head of the places, but atleast the first few tournements you can win. I have faced Lucy maybe 5,6 times on my GBA, and lost to her each time. Atleast the battle frontier gives you a sense of accomplishment by beating the some tournements and getting BP, until the pokemon get tougher....