Hello everyone! I'm having a hard time trying to figure which model of a high speed contra do I purchase. I'm not sure if l should buy something fancy like w&h or if I should get something relatively cheap and durable like coxo because I'm still a student. Between w&h, sirona and coxo, which is the best? and what are the pros and cons of each one? if there are any other suggestions you can help me with I'd like to hear them. Thank you!