Yes, for wired it will default to the lowest common speed, so 100MBit will be the fastest you will get, which is about 12MB/s

For wireless both are 802.11n compatible, so as long as your router is also 802.11n compatible then you should be able to transfer at faster speeds then the older 802.11g. The older 802.11g has a theoretical speed of 54Mbit, which is about 6.5MB/s, whereas 802.11n is between 150Mbit for a single aerial device, to 300MBit for a 3 aerial device... But you are more likely to achieve something around 100MBits/s which would be a transfer rate of about 12.5MB/s, which as you can see is about Ethernet wired 100Mbit speeds. But WiFi speeds are not really that sustained so you might get a slower overall transfer. Plus you need to be close to the router, and also to ensure the router is set to use 802.11n and that you have no 802.11g based devices connected to the network, otherwise it will switch the router into mixed mode and slow the speed down.

As you can see even 802.11n really isn't that fast these days. The fastest speed I've achieve transferring files over WiFi is about 33Mbit/s downloading from broadband, which is about 4MB/s, so not too bad.

You are probably best using a wired network for the laptops. Rather than a crossover cable between the 2, which can be a bit fiddly to setup and get working, why not just connect each to your router via Ethernet cable? Put them on the same Workgroup and make sure share files is switched on on both, and at least one directory or HDD is shared and then you can easy copy files across as the maximum speed 100Mbit Ethernet can handle.