Steel vs Plastic bases

[Stormwind]

I finally got a bunch of Sally 4th boxes with these inlays:

http://wargamesbuildings.co.uk/epages/950003459.sf/en_GB/?ObjectPath=/Shops/950003459/Products/c007/SubProducts/c005-0001[1]

And now I am wondering if I should just get steel bases from now on in order to have magnetised bases from the get go.  These guys sell 40mm by 20mm bases at £1 for 7 which doesn't seem bad:

http://www.productsforwargamers.com/steel_bases.html

And these guys make circular bases in 25mm and 40mm which would suit my command bases perfectly:

http://www.freewebs.com/pwsltd/steelbases.htm

Is there a disadvantage to steel bases? Do they chip easily?

[Aldhick]

I don't have the experience with steel bases.. I just use magnetic foil sticked to the bottom of the plastic bases. I transport my minis on metal trays in my briefcase. It holds firm enough not to fall off during the transport and yet it lets go easily when I want to remove them from the tray. Completely satisfied :-)