How should I choose between JAS500Q and JAS700Q? How tangled!

I have tried to play both of the two models mentioned by the landlord of Jabert's alto saxophone at the Shanghai Musical Instrument Exhibition. Tell me how I feel. The sense of control of 500 and 700 is almost a comfortable key, and the playing resistance of 500 is slightly lower than 700, which also affects the timbre. The timbre of 700 is heavier than that of 500. A very good innovation of the 700 is that there are three buttons on the upper handle that can be adjusted. This experience. Beginners can use Jeppert 500 series, and if they plan to change the tube, choose Jeppert 700 series.