I have heard of people having problems claiming for repairs with a mack warranty, by the time you take this out you'll be saving even less money.
I would not take out any extra warranty anyway, just bringing it to attention of others. I don't fill in any warranty on anything I buy until it goes wrong and sometimes it gives me more warranty time.
Here's a little story that happened to me about 10 years ago,
I bought a washing machine as I thought form J Lewis, it went wrong I went into the store, it was just over the warranty period and the girl was not listening or agreeing any of my request for leannesses in regard to the warranty, so I asked her to get the manager out, after a lengthy discussion he relented and said he would send round a replacement machine whilst mine was being repaired, all went well and the repaired machine was delivered working well, they took back the replacement machine, the next day I checked my receipt and too my amazement I had bought this machine at a different wholesalers, all I can say is thank you J Lewis, What I think has happened the manager thought the girl had checked all the receipts etc.