External USB-2 Pioneer 111D

Pioneer have an external USB & Firewire 111D model that I found on-line, I had a few questions on this unit and was hoping to get help here.

1- Being an external version is it exactly the same as the internal versions or are these types of units modified ?

2- Is it slower or is its performance affected/modified being USB-2

3- What are all the possible differences between the internal models and an external model.

http://www.blankmedia.ca/proddetail3.asp?id=1120

1.To me it doesnt look like a Pio manufactured combo. Probably just a 111d put in a box.
2.I remember seeing speed charts where USB enclosed drives reached 14x instead of 16. I think it was on cdrinfo.com review. Not sure if it is really so and whether it is the case with Firewire.
3.Should you want to reflash it with modified firmware, you are better off with an external version, such as 8.26 ext from TDB that will make your drive 111L - RAM and labelflash.
Cheers.
p.s. Now that I’m curious myself, let me know if there is a usb speed limit.

It depends on the drive and on the chipset of the USB enclosure. Some drives indeed reach 16x via USB, others are basically limited to 12x, and some even fail.
See http://club.cdfreaks.com/showthread.php?t=175536

Pioneer does not sell such external drives, others do.

FidelC explained already.