A3 and A4 colour laser - which one would you go for?

I'm looking for 1 x A3 and 1 x A4 colour laser printers for a small business. The A3 will be used by the CEO for his own personal needs and the A4 by his PA. Load is likely to be light to medium.

I've had quotes for the following that all come out pretty close.

A3

1. Dell 5130cdn
2. HP LaserJet Professional CP5225n
3. Xerox Phaser 7100vn
4. Oki C822

A4

• Dell C2660dn
• HP LaserJet Pro 400 colour M451nw
• Xerox Phaser 6600vn
• Oki C511dn

This client already has 3 x Xerox 7232s and 1 Xerox Phaser 4510 which have been completely troublefree for usage and install compatibility. We are exclusively W2012R2, W8.1 and W7.

Any opinions?