Thanks, I've picked up a few things that are interesting from these replies. I'd say cooler would be better as this thing is only tiny and would like to make it run as smoothly as possible.
Is it a bad idea to run two different brands of ram on the same PC as I think I'll just go 8gig now and add another 8 in a few years when need?
Thanks.
Cooler is better and lower voltage means it uses a little less power but a little higher voltage can sometimes improve stability depending on the memory that is being used.
I would base a decision about what memory to use more on the reputation of the brand and the customer feedback and reviews for your exact machine when using those particular memory modules that you are interested in purchasing. I can only speak from my own experience. As long as you select the right memory... I approve of Crucial brand for use in Macs with confidence. I have used Crucial memory for many years on Windows PCs and I am using that in my mid-2011 Mini. I have used Kingston brand memory in the past but only with Windows PCs. I believe Kingston makes high quality memory but they are usually more expensive. I have never had a problem with Kingston brand memory when I have used it in the past.
The other brands I often used reliably for PCs in the past were Corsair and GSkill brands. The knowledge and opinions I have about the other brands of memory for use in Mac Minis comes from reviews in this and other forums. Many users have no problems with other brands on their Macs. At this time I can only personally recommend Crucial for the Mac Minis and suggest Kingston based on current reviews and experience with them as being a long time vendor of premium quality memory.
Mixing different brands of memory may work for you and others perfectly well but in practice it is something I always try to avoid. I have mixed memory in the past with older Windows PC systems when I didn't have any other choice and despite my resistance it often has worked fine. The PC system manuals usually explain recommended optimal configurations that you can use. However, I would rather spend a little more money for matched pairs and dual kits with the same specs of the same brand than to hassle with problems showing up in the future because of incompatibilities. Using dual kits also makes it much easier to debug memory problems since you are using the exact same brand and type in two memory banks. I don't expect my more expensive way of doing things to be the way everyone else has to do them. It's my answer for trying to avoid potential computer problems.
You can go with only 8GB now. Memory prices have always fluctuated and seem to have gone up considerably in the last month. I would recommend buying a matched pair or dual kit 8GB (2 x 4GB) and completely removing the stock memory... but many Mac Mini owners have reportedly had no problems using a single 8GB (dual sided or chips on both sides) stick in one bank or adding one of the stock 2GB (dual sided) modules to one of the other banks for a total of 10GB in their late-2012 model Minis. If you mix memory you want to try to match the specs of the memory you purchase with the stock memory...same voltage, CL timings, etc..
