Upgrade or get a new one- Macbookpro. 15. 2.6Intel Core 2 or Mac mini

At home I have my old MacBook Pro 15 inch - 2.6 Ghz Intel Core 2 Duo with 4Gb 667 MHZ DDR2 SDRAM. conected to an apple cinema dysplay With system10,8,2 and 250GBof Disk.

My most demanding usage is working with apperture pictures of about 12MB and library of 70GB. Creating presentations with Keynote and using some video.

Lattly I found that my computer goes slowl, and I have run some software to "clean the computer and organize the disk", It has improved but still is slow, even my MackBook Air (2nd genereration is faster).

I am thinking on changing the hard disk from 250 (Used 200), to a bigger may be "fusion", disk and upgrading from 4GB to 8 Gb faster RAM, or just may be switching to a New MacMini, since I use my macbook air for laptop....

MacMini

• 2.3GHz quad-core Intel Core i7
• 4GB memory
• 1TB hard drive¹
• Intel HD Graphics 4000

Any Sugestions....will be worth it the inversion of the "old Powerbook" is beggining of 2008.....If I get the new Mac mini....I will be loosing the screen of the MacBookPro......

Any sugestions will be really appreciated......

Thank you