colocation
if your server have hardware fault then you need to drive to the data centre and change the part.
you are sharing 2Mbps bandwidth with the whole rack (what i heard, not to be confirm)

dedicated server
if you done your home work, you may get the provider with SLA - 100% network uptime gurantee, 2 hours gurantee hardware replacement.
connection will be little slower and if you can get a west coast server (you will get the neartest provider to Malaysia) i do not feel any difference if just web browsing and emailing.

DA and Cpanel both are great control panel. I used both but prefer DA. (my personal opinion)

go for directi. they offer cheaper prices. never used onlinenic.

lastly, good luck looking for a provider.

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Danny Goh
GetHosted.com.my