The additional power is unlikely to be necessary. Most people never have their amps output more than a handful of watts (usually without knowing it).
This is incorrect, and represents a common misunderstanding of the difference between continuous output (average/nominal output) and momentary/peak output.
Dynamics - the difference between loud and soft - are critical to good sound quality. Dynamic peaks in music are 12-15dB higher than the average output. Each 3dB requires a doubling of power. An amplifier without sufficient headroom to accommodate these peaks will go into clipping, which causes distortion and degradation of sound quality.
Yes, in most home audio situations your AVERAGE output is only 4-5 watts at a moderate loudness (assuming reasonable efficient speakers, with sensitivities around 90dB). But to accommodate dynamic peaks without clipping when pushing 4 watts continuous, your amp would need to be capable of 64-128 watts of peak output.
Minimal clipping is acceptable, as it is not particularly audible. However, clipping distortion increases exponentially as more and more of the signal is cut off. Because the relationship of loudness, amp power, speaker sensitivity and clipping is not well understood, it is my belief that clipping is extremely common. Most people are clipping their amps with regularity, but they assume that the harsh edge and compressed low end they are hearing is just because their speakers aren't good enough!
Obviously, which of these amps is more attractive is purely subjective. A fair, market-based price for the integrated is $80-90...it is up to you to decide if this is "too high". The performance specs of the two units are close enough as to be relatively indistinguishable. The only significant objective difference between the two is their output power.