The Beats Solo Pro Wireless and the Marshall Monitor 2 ANC Wireless are two decent pairs of on-ear headphones with Active Noise Cancelation. The Beats Solo Pro have a noticeably better ANC feature that blocks out more noise and have a longer battery life on a single charge. On the other hand, the Monitor 2 ANC have a more comfortable fit and they can be used wired, even if the battery is dead. Both have an app you can customize your listening experience.

The Marshall Monitor 2 ANC are good-sounding, mixed usage on-ear headphones with an efficient control scheme. They are lightweight yet durable, and have a good battery life and a great wireless range. They're also noise-canceling headphones which should be good enough for public transit. However, their ANC is a bit weak compared to other noise canceling models.

Good for neutral listening. They have a well-balanced audio reproduction that packs a good amount of bass and isn't too forward or recessed with instruments and vocals. 

Above-average for sports. They're lightweight, breathable and stable enough when jogging. Their wireless design also makes them less likely to fall and they have a great and efficient control scheme. However, they're not the most portable headphones and they will slide off your ears during more intense workout routines.

Sub-par for gaming. They have a bit too much latency, a mediocre integrated mic and no customization options. Also, they're not the most comfortable headphones to use for long gaming sessions but at least they come with a versatile audio cable with an in-line mic that is compatible with most console controllers and PCs.

The Beats Solo Pro are very well-built on-ear headphones that have a fairly neutral sound profile that's a bit on the exciting side, with a bit of extra bass and treble. They have a premium feel and sleek design, on top of having a very good active noise cancellation feature that blocks out ambient noise well. On the upside, the 24-hour battery life should be more than enough for most people. However, they're very tight on the head for some people, which becomes quickly uncomfortable, and they can only be used via Bluetooth as the charging cable doesn't provide audio but they are instantly connected to your apple product.

The Beats Solo Pro have a well-balanced sound profile, although they're a bit on the excited side with a bit extra bass and treble. On the upside, they perform quite consistently and the peaks and dips in the response aren't very audible.  These on-ear headphones are great to use during your commute or at the office while enjoying your music with good fidelity. They'll be better than over-ears for sports, but still won't be a great option. Also, they aren't designed for gaming and their microphone performance is quite lackluster so it won't be great for phone calls either.

As a resume, we would say its a decision of style. If you prefer a modern slick design that goes along the apple legacy and you are a fan of autotune, you should go for the beats.

If you heart belongs to rock'n'roll and if marshalls own legacy appeals to you - go for the Monitor II, that still comes with a chinch plug.