Like usual the Apple Techs you spoke to have NO Clue.
Look in the Documentation for your MBP, a copy is on the hard drive, and it will give you Instructions on how to change both the RAM and HDD. Apple would not provide Instructions in the User Manual if it Voided the warranty.
So it Does Not Void the Warranty.
If you want a Definitive Answer look in your Manual.
Since Apple provides instructions in the USER manual on how to change RAM and HDDs, I fail to see how that would void the warranty for rest of the MBP (unless damage is done in the installation). Naturally the new RAM and/or HDD would not be warranted by Apple, but the manufacturers warranty would apply to those items.
Apple maintains uniform warranty rules worldwide unless modified by local law/regulations.
Changing memory and storage is permitted on the MBP non-Retina machines and Apple even clasifies the ram and storage as user-upgradable items. Apple does add the caveate, however, that if you cause any damage doing the upgrade the warranty will not cover the damage.
In the past there have been some Apple techs who insisted the third-party components be removed before they would service the computer. Lately no one has said they had that happen to them.
Go to the UK Crucial website - http://www.crucial.com/uk/ - and download the app from the System Scanner tab. It will show you the right RAM kits and will make recommendations for SSDs. I've a Crucial 512GB my series SSD right now and am anxiously awaiting the release of the M500 series because I want to 'upgrade' my SSD to 960GB. If you don't need that much storage, I can heartily recommend the m4 series - you can even accomplish firmware upgrades on your Mac, unlike with some other vendors.
Your concern about wanting to hear it directly from Apple is understandable...but if you read the User Guide that came with your MBP and that is on the hard drive and on-line (click Support in the upper right side of the menu bar for this page, then Manuals, then find the PDF file for your machine) you will find memory and storage specifically called out as user upgradable. Apple would not say that if it would void the warranty. You can be sure their legal department would not allow publication of something that could get them sued.
Take a look at the link Clinton gave you...it is great and very useful.
You really can't go wrong with either Crucial or OWC...they have really good support and return policies and warranties if there are problems. I bought my MBP and iMac both with custom setup here in the US and then upgraded the memory myself at less than half the price of Apple's memory and both work just fine.
Be sure to buy the AppleCare extended warranty, for the MBP it is expensive compared to a desktop due to the protatiblity factor. But the extended warranty gives a lot of comfort. And you don't HAVE to buy it with the MBP, just within a year of purchase of the MBP...and Apple will send you a couple reminders before the end of the year of ownership reminding you that your anniversary date is coming and you need to buy AppleCare before that date.
Good luck with your purchase.
That's what I did with my machine - bought the least amount of RAM and slowest, least expensive hard drive and then immediately installed 16GB of RAM and then, a month later, got my Crucial SSD.
The 'new' MBP's don't come with the same user manual that the 2011 and earlier models had - just a quick setup guide. So you won't find the upgrade info in a new user manual. But there are tons of Apple guides ou there - like this http://support.apple.com/kb/HT1270?viewlocale=en_US one - that take you step-by-step into replacing RAM.
Hopefully, you'll be able to get the information from a knowledgeable Apple tech - I'm sure that you can find one!
Hi Guys, I looked up the Manual for the 15" 2012 model, on the Support page on the Apple Store and this is what I found:
"This warranty does not apply: (a) to consumable parts,
such as batteries, unless failure has occurred due to
a defect in materials or workmanship; (b) to cosmetic
damage, including but not limited to scratches, dents
and broken plastic on ports; (c) to damage caused by use
with another product; (d) to damage caused by accident,
abuse, misuse, liquid contact, fire, earthquake or other
external cause; (e) to damage caused by operating the
Apple Product outside Apple’s published guidelines;
(f) to damage caused by service (including upgrades
and expansions) performed by anyone who is not a
representative of Apple or an Apple Authorized Service
Provider (“AASP”); (g) to an Apple Product that has been
modified to alter functionality or capability without the
written permission of Apple; (h) to defects caused by
normal wear and tear or otherwise due to the normal aging
of the Apple Product, or if any serial number has been
removed or defaced from the Apple Product"
What does the "This warranty does not apply" mean?
It's different to the section which says "WHAT IS NOT COVERED BY THIS WARRANTY"
I couldn't find anything about how to upgrade.
While I cannot speak for the geniuses at your local Apple store (there have been complaints on here about some of the UK store staff, not sure which store) you should not have a problem. The worst case anyone has discussed has been their insistance on having the third-party components removed and OEM back in.
In my area, though, haven't heard of anyone having that experience. Our Apple stores (three within ten miles) are extremely helpful and cooperative.