I have two veileds and have had a female panther in the past. I love, love, LOVE my veiled's - they have my heart and I'm not sure if its the casque, the colors (my male is a spectacular turquoise) or the varied, and often sassy attitudes! I have been lucky in that both my veileds have great personalities. My panther was also a lovely little lady, although less colorful than my veiled's but she had a sweet personality and was very patient with my handling of her, which is important to me. My next quest is a male panther, if I can take a step back from loving the veiled's (I am thinking of another male veiled, even now, although I have a line on a Mitsio in the next few months!)
Its really a matter of preference - I didn't find the differences in husbandry enough to really have a problem tweaking it for either species. If you want colorful then a male panther is the way to go!
One thing is certain, once you own a cham, you'll never look back no matter what the species!!