I have the seat you linked to. It is on my dhs bike.
It changes the way you step on and off the bike. If you normall step on the bike by swinging your leg over and above the seat from behind the seat, I am sure you will be fine, if you can fit it on your bike.
I step onto the bike by raising my knee and putting my foot over the cross bar, but you cant do this with this child seat on, as the seat will be in the way. Also, bear in mind if you have to break abruptly (younger child on bike swerving into your path for example) and come off, you cant jump down and stand with your bike between your legs, as the child seat is there. You have to stand, swing your leg over seat and then make a very controlled stop and get off.
I have a full suspension and I can fit on my bike. Other issue, I could not personally have that childseat with any bike, due to hip issues (spd).
My husband has the seat on his bike, as he is very fit, a skilled mountain biker, and for him it is not a problem at all, as he would be more than happy to try some acrobatics on his bike!