Just wanted to get some second opinions...
I'm considering buying one of these from
refurbished, not sure which:
MBP 2.3GHz dual-core i5 -- £850 ($1380)
iMac 3.06GHz dual-core i3 -- £820 ($1330)
It is going to be used only for music recording/production purposes, using ILife 11 GarageBand - mainly working with real not software instruments. I will be recording and saving from an external FW800 drive.
If I get the MBP I will be upgrading it to a 500GB 7200rpm HD (same as the iMac), and whichever I get I will upgrade to 8GB RAM.
I need to be able to occasionally move the computer a few metres to lock it in a secure room when not using it, so for this reason the easier portability of the MBP would be convenient but is not essential.
The main question I am looking for some kind of answer to is whether there would be much difference at all for music production, in terms of speed/performance/latency/reliability between the two models? On paper the only real difference would be 2.3 i5 versus 3.06 i3 processors... I suspect the 3.06 i3 is a better processor but how much better is it?
Also I am thinking the MBP might be more DIY upgradeable than the iMac so a better choice as a long-term investment.
Any advice or thoughts greatly appreciated.
I'm considering buying one of these from

MBP 2.3GHz dual-core i5 -- £850 ($1380)
iMac 3.06GHz dual-core i3 -- £820 ($1330)
It is going to be used only for music recording/production purposes, using ILife 11 GarageBand - mainly working with real not software instruments. I will be recording and saving from an external FW800 drive.
If I get the MBP I will be upgrading it to a 500GB 7200rpm HD (same as the iMac), and whichever I get I will upgrade to 8GB RAM.
I need to be able to occasionally move the computer a few metres to lock it in a secure room when not using it, so for this reason the easier portability of the MBP would be convenient but is not essential.
The main question I am looking for some kind of answer to is whether there would be much difference at all for music production, in terms of speed/performance/latency/reliability between the two models? On paper the only real difference would be 2.3 i5 versus 3.06 i3 processors... I suspect the 3.06 i3 is a better processor but how much better is it?
Also I am thinking the MBP might be more DIY upgradeable than the iMac so a better choice as a long-term investment.
Any advice or thoughts greatly appreciated.