I had a couple of cityline venice, paris two yrs back..from my experience, these guys are very compact with fairly short internodes between the branches...i wouldn't bother to pinch it because the plant is tight and compact already..they tend to grow slower than the common Endless Summer,.one thing about the citiline series is - small size is great, little pruning if ever is needed...but blooms on old wood..and some of my clients' cityline plants didn't make thru this winter - it's a truly wild and crazy winter here in Jersey...because you are in zone 5 - you really need to protect the plants during winter if you want blooms next yr..jmho..btw - venice looks GREAT in deep purple (the color of this series is very vivid and intense..Paris should be in the red form..)

Yeah, I am planning on heaping some mulch over them for the winter. Hopefully that will be enough.
Thanks!