Mmalin is right about the X-2s being efficient. But, in my opinion, more power for the speaker may or may not be overkill. It depends on your room size and listening preferences (types of music and volume levels).
With my pair, I've found that more power and current improves the dynamics of the speaker. I use a pair of Spectral DMA-360 Universal monoblocks which deliver over 500 watts and 90 amps of current per channel into the 4 ohm load of the X-2s.
I'm guessing that the Levinson 33 amp will work better than the 33H with the Alexandrias, since the 33 has more power and current. But that's just speculation. I've never heard either amp on the X-2s.
With my pair, I've found that more power and current improves the dynamics of the speaker. I use a pair of Spectral DMA-360 Universal monoblocks which deliver over 500 watts and 90 amps of current per channel into the 4 ohm load of the X-2s.
I'm guessing that the Levinson 33 amp will work better than the 33H with the Alexandrias, since the 33 has more power and current. But that's just speculation. I've never heard either amp on the X-2s.