In my opinion it would be a waste of money at this point to replace your computer with a newer model. Your MacBook Pro should be more than capable of performing tasks without running slowly, which leads me to believe that there may be an underlying software or hardware issue.
Here are a few troubleshooting steps that you can try, see if they help to improve your computers performance:
Run the Apple Hardware Test
For information on how to run the Apple Hardware Test on your computer, please see
http://support.apple.com/kb/ht1509.
If the Apple Hardware Test reports that there is a hardware issue with your computer other than the RAM or hard disk (as these parts can be easily replaced), either contact Apple regarding the matter (if you still have AppleCare) or look into replacing the unit if repairs would be too costly.
If the Apple Hardware Test does not report any errors, proceed with troubleshooting the software on your computer.
Repair permissions
- In the Finder, click on Go and then click on Utilities.
- Open Disk Utility.
- Select your computer's boot volume (typically labeled "Macintosh HD") on the left hand side.
- Click on the First Aid tab and then click on Repair Permissions.
- Wait for Disk Utility to repair the permissions on your boot volume, then restart your computer.
For more information on repairing permissions, please see
http://support.apple.com/kb/ht1452.
Reset PRAM
To reset the PRAM on your MacBook Pro:
- Turn off your computer.
- Press the power button to turn the computer on.
- Hold down the Command-Option-P+R key combination until you hear the computer chime twice.
- Release the keys and allow the computer to boot up.
For more information on resetting the PRAM (Parameter RAM), please see
http://support.apple.com/kb/ht1379.
Safe Boot
Performing a safe boot will clear the caches and perform other maintenance tasks that may resolve software related issues with your Mac.
To perform a safe boot:
- Turn off your computer.
- Press the power button to turn the computer on.
- Immediately press and hold the Shift key on your keyboard when you hear the computer chime.
- Release the Shift key when you see the Apple logo appear on your screen.
- Once the computer has booted up, restart it to boot normally.
For information for performing a safe boot, please see
http://support.apple.com/kb/ht1455.
Try another user account
- Click on the Apple menu.
- Click on System Preferences.
- Click on Accounts.
- Create a new user account.
- Log out of your current account.
- Log in to the new account.
- See if the computer is still performing slowly.
For more information on creating new accounts, see
http://support.apple.com/kb/HT2542.
Re-install the latest combo update
Installing the latest combo update package may repair corrupted or damaged files within Mac OS X.
- Click on the Apple menu.
- Click on "About This Mac".
- Verify which version of Mac OS X you are currently running (e.g. 10.6.6).
- Download the appropriate combo update installer from Apple's support website at http://support.apple.com/downloads#Combo
- Install the combo update that you downloaded.
If none of the above steps correct the performance issue with your computer, then I would recommend looking into re-installing Mac OS X to rule out the possibility of a software related issue.
You could also look into upgrading the hard disk in your system to help improve performance, either by replacing it with a 7200 RPM drive or a solid state drive (SSD), which would be more cost effective than simply purchasing a new computer.
Hope that helps, have a great day!