Short of using a fully sealed IEM with foam eartips, which the Xelento is not, you're better off with a pair of Bose QC35 II. Their Active Noise Cancelling is amazing for commuting and they have great bass extension. They see the most use between all my headphones and IEMs simply because most of my listening is during my daily commute... they noise cancelling really puts you in your own bubble so to speak. I also own the Sony MDR1000x and they do not do as well on transit, bumpy bus rides falsely trigger the ANC more often on the 1000x so can't recommend them for that use.
That said, I don't mind the Xelento's on transit, just don't expect any kind of analytical listening. The bass is elevated as part of the stock sound tuning so that does not suffer horribly on transit. In terms of isolation, do I enjoy Xelento less on transit than my fully sealed SE846 with silicone tips - yes.
To throw a curveball at you, IEM's don't usually fit my ears well however the Xelento never breaks the seal on me. I've used them for 5+ hours on transit in one day and they never broke a seal. For that reason, it makes me actually prefer them over the SE846 as I don't have to fiddle them, put them in and forget about it.
I'll use the Xelento on my commute tomorrow (bus, subway) and try to give you a more detailed rundown of what to expect.