1. Whammy Bar: The main difference, obviously, is the presence of the whammy bar on the model with the whammy bar. The whammy bar, also known as a vibrato bar, allows you to manipulate the pitch of the strings by moving the bar up or down. This adds an extra level of expressiveness to your playing.
2. Tailpiece: The guitar with the whammy bar has a different tailpiece than the model without the whammy bar. The guitar with the whammy bar uses a Floyd Rose-style locking tremolo bridge, which provides enhanced tuning stability and allows for more extreme whammy bar usage. The model without the whammy bar has a fixed bridge, which provides a more solid, stable tuning experience and is generally preferred by players who don't use the whammy bar much.
3. Body: The guitar with the whammy bar has a slightly thicker body than the model without the whammy bar. This difference in body thickness is due to the need to accommodate the Floyd Rose-style locking tremolo bridge, which requires more routing of the body.
Overall, the main difference between the PRS Paul Allender SE guitar with the whammy bar and the model without the whammy bar is the presence of the whammy bar and the related differences in tailpiece and body thickness. If you're looking for a guitar that provides versatile sounds with the option of using a whammy bar, the model with the whammy bar is a good choice. However, if you prefer the stability and simplicity of a fixed bridge and don't plan on using the whammy bar much, the model without the whammy bar may be a better option for you.