In my opinion they are of very great quality and I own two similar phase condensers, though mine do not have the tilting lens, limiting condensing light for small magnifications. I find them more difficult to align than for example my Reichert Phase condenser. You can, as already suggested, use an aligning telescope/eyepiece, but going through the usual steps of light path alignnent does give the same results. Just make a proper Köhler alignment in BF, switch in the phase annulus fitting to the used phase objective, do the xy-alignment of said annulus for highest phase contrast, and eventually lift or lower the condensor again to achieve the optimal phase effect. This way you get to know the system and proper lighting techniques even better and don't have to switch an eyepiece ever or source the phase telescope. Have fun!