Tokaido/Sanyo shinkansen Pass?

We plan to visit Japan in April of 2015 and would like to purchase in advance a 7 days JR Pass and Tokaido/Sanyo Shinkansen (5 days pass) for using Mizuho & Nozomi Shinkansen. Is there anyone has experience of purchasing Tokaido/Sanyo pass?

http://www.japanrailpass.net/eng/en004.html
Remarks:
*1 The JAPAN RAIL PASS is not valid for any seats, reserved (incl. Green Car) or non-reserved, on �hNOZOMI�h and �gMIZUHO�h trains.

OP is most likely referring to this new 5day pass.
http://www.japan-guide.com/e/e2361_tokaido_sanyo.html

its a new pass, so i think not many ppl have used it yet.
And the page even described its close to not beneficial to use this pass over the regular 7day nationwide JRpass other than able to ride the fastest shinkansen available..

Hi OP.
Any reason you want to pick this pass over the 7day JRpass?
The process of purchase is the same as the 7day JRpass, ie you need to buy it before entering japan

And just in case you think you need to use the Nozomi/Mizuho because you have already planned your trip down to the minute and need to take them to make a connection, remembre that the train schedules for April 2015 are not published yet, so if you have used Hyperdia or something similar, you might very well find that the train you want will not be running in April, or that there will be a suitable Hikari or Sakura.

It's hard to help you without knowing where/when you enter Japan, then when you will use the passes and where/when you leave Japan.

I bought the Tokaido/Sanyo Shinkansen 5 days pass and used it last week. Frankly, I wished I had bought the regular 7 day JR Pass (though I only would have used it 5 days). Just to get it exchanged, we had to go to three different JR offices (no one seemed to know what it was or how to activate it). Once it was finally activated, we had trouble with redemption just about every time. At the very least, a manager or supervisor had to be called to explain it to the clerk. To use it for the non-train applications, we had similar problems -- eventually it was accepted, but it was a fight every time (it helped to have the print-out explaining the applications of the pass). It was nice to try the Nozomi train, but other than being slightly faster it was no different from the other trains on the line.