There are number of differences that have struck me between the two different modes of transport.
SoundOn my motorbike all I pretty much hear is the noise of the engine, and on roads when I can do 50mph (it's not a very powerful bike) the wind noise. I'm wearing ear plugs so the roar is duller than it would be otherwise. On the bike I get to hear the traffic, and occasionally when there are no cars near, the sound of my tyres on the road. It's nice to have a variation in the audio diet.
SmellI can also smell more, but that's probably more to do with the slower speed, rather than the difference between a cycle helmet and a full face motorcycle helmet. There's a smell zone a couple of streets around the local Chinese takeaway. It's not strong or unpleasant, but just a background feature.
SpeedGoing at around 10mph instead of 50 also means that you can see more. On my new route to work there's a field without a hedge and I can see the winter wheat sprouting already, so over the next few months I'll be able to see it grown and ripen. You also have more time to see the potholes and avoid them. (I could rant/blog quite a lot about potholes, but I'm very restrained, so that's all I'll say on the subject.)
Sociability (OK, I'm stretching the Ss a bit)If you're a car driver (or cager as bikers call it) then you probably don't greet other motorists as you approach them. However both types of bike riders do - just a nod on a motorbike as you're not going to be heard if you said anything. I have to remember to nod at the right sort of person as a biker would probably think it strange if a cyclist nodded at them.
AfterglowAt the end I'm usually warmer when I've been cycling, even though I have fewer and thinner layers. There's also that post-exercise high due to endorphins, or smug self righteousness, or who knows what.
There's an app for that - StravaOne of my brothers introduced me to the Strava app which allows you to plot your speed during your cycle rides (and runs should you want to). You can also measure your progress on "segments" of road against other people. I find it useful to see my speed improve as I progress from really unfit to unfit. There's one segment on my way home and that's the only bit where I push myself at all, though I'm going to find it hard to beat the time I set the other day when I had a tailwind.
Both forms of transport involve faffing at the start and the end of journey - special clothes, making sure that wallet, keys and phone get transferred to these clothes. There's extra faffing for the bike to do with lights and putting my bike bag on the rear rack. On the other hand bike clothes are so much lighter than protective motorbike gear.