The sampling rate (which you can control on the Vyper but not the Mosquito) determines the interval (in seconds) that the computer records dive data. The Mosquito samples every 20 seconds, and that is what you see replayed when you review the dive on the unit itself or using the interface and software. The Vyper, on the other hand and as mentioned above, can be adjusted as to how often it samples dive data (10s, 30s, etc).
The other control feature you mention is what Suunto calls the "Personal Setting." You can choose between three levels of conservativism depending on your personal preferences (health, age, diving conditions, etc.) But this setting does NOT effect the sampling rate, they are unrelated. You can also change the altitude settings. These effect the algorithm.
FWIW, I use a Mosquito with over 200 dives on it and love it, and my buddy dives a Vyper and loves it.