Access time is a fundamental property of the drive. It is the combination of two values: seek time, which is the time it takes to move the heads to the correct track, and rotational latency, which is the time required to wait for the requested sector to rotate under the head. Obviously these will vary somewhat (depending on where the requested track is relative to where the head currently is at, and where the requested sector happens to be on the disk when the head gets there) which is why it is listed as an average value (and why you'll see slight variations from test to test). It isn't going to be affected, at all, by the interface used to connect the drive -- as your test results show.
Burst speed is the throughput of data read out of the drive's cache (all drives have some RAM inside them used by the drive's firmware to cache data that may be requested in the near future). That will be limited by the interface speed, since RAM is much faster than any HD interface, but it has only a limited impact on overall performace of the drive.
Transfer rate is the bandwidth the drive can deliver when streaming data from contiguous sectors and tracks on the drive (if they're not contiguous, seek comes into play again). This is purely a function of the rotational speed of the drive and the density of data on the platters, and it is lowest on the inside tracks of the drive and increases as you move towards the outermost tracks. Of course it can be limited by interface speed if the interface is extremely slow.
In your case, something is limiting the USB speeds. Hi-speed USB 2.0 should be capable of reaching close to 40MB/s (the theoretical speed of 60MB/s isn't really achievable in practice), but it's clear from your burst speed results that something -- the controller, the chipset in the drive housing, a hub that might be in between them, or the drivers -- isn't capable of that.
But that's really not important since you clearly have other connection options at your disposal.
When the interface is not limiting performance, the WD is clearly superior in access times and transfer rate, so it's really no contest. As JBI says, that looks like the difference between 7200rpm and 5400rpm drives.