Two distinct advantages in favor of purchasing the same expensive OP / Tech carrying strap:
1) Both camera straps can be freak with a mechanism and remove. For cases where the strap is long time a hindrance. The remaining at the camera, short ends of the strap can be put together firmly when OP / Tech. This results in practice a very practical, short Kameragurt, which allows you to hold the camera comfortably and securely in your hand. When Lowepro SLR strap the fitting together of the ends is not provided, then dangling in mid-air.
2) The OP / Tec Pro loop is threaded with thin, robust bands in the side brackets of the camera. When using the camera, it will inevitably mean that the belt is twisted. What is not a problem for the OP / Tech because the resulting distortions affect only the lower part of the belt, the tapes that are directly connected to the camera. The slightly wider, lower part of the strap not tangled up little up. The situation is different when Lowepro strap. Here a common, wide loop is threaded into the camera mounts. As a result, that twisted the completely non-neoprene part of the belt in use on both sides. You know the problem so sure himself from the spiral cable of a landline phone, which also tends over time to such effects.
Advantages of Lowepro: The anti-slip effect of the neoprene shoulder strap is a bit better than the OP / Tech. In addition, the Lowepro Belt features an integrated pocket for memory cards, but I've never personally used and would not use.
* My Opinion: As the OP / Tech belt more or less will cost the same money and in my view provides better functionality, you should pick up the OP / Tech Pro Loop. Due to the loop solution it will be suitable for almost all SLR cameras. The advantages of the Lowepro belt weigh its disadvantages compared to the OP / Tech not to.
Although I the Lowepro Belt no longer apply. The Fototaschen- and Backpacks from Lowepro are first choice, therefore I have only pockets of Lowepro. ;-)