To make an informed decision you first need to understand a few basic concepts and some pros and cons of each system.
Firstly there are the concepts of precision and accuracy. These are two very different properties and each is important in their own way. On the face of it they may sound the same, but they aren't.
Precision
This is how close to the real value your measurements are. This is the "±" value that datasheets list. It's how close a match to the actual temperature the measured temperature is. So a ±0.5° measurement could be anywhere within half a degree of the actual temperature.
Accuracy
This can also be considered as the resolution of the measurement. It is how fine a difference in temperatures the device is able to measure. For instance you may be able to detect 0.0125° differences. This is mostly defined by the resolution of the ADC in the device.
And now the pros and cons:
Digital
Pros
These devices can be factory calibrated for a more precise reading. The accuracy is usually pretty good too, but is fixed by the design of the device. Communication is generally reliable and wire length doesn't generally affect the values reported.
Cons
Communication protocols can have some large overheads limiting the number of samples you can take per second (not just on one sensor but across the whole array of sensors). Excess EMI noise (especially from engines) can corrupt the communication signals over long connections unless extra care is taken (such as implementing a balanced line communication medium).
Analog
Pros
Very simple to connect up and samples can be read very rapidly. Accuracy is determined by the ADC you choose to use.
Cons
Wire length can have a detrimental affect on the values read unless special wiring and sensor schemes are used to cancel out the resistance of the wires. Noise induced into the wires is very hard to detect or cancel out and can give spurious results. Requires more complex mathematics to calculate a resistance.
Summary
So in short: Digital can give you more reliable communication of your sampled values over longer distances but at the cost of reduced sampling speeds.