I use both with my HT system,
The first thing to do is set it up to be a HT system correctly, that included proper center channel speakers and placement of the surrounds. Dolby has the setup proceedures and requirements for speaker dispersion on their website--use it!
After dealing with people adding surround to 2 channel then complaining nothing works correctly--I just set it all up by Dolby standards and that solves most of their problems. If they have their 2 channel speakers that don't fit HT specifications, bipoles, open baffle speakers, Bose 901's or ESLs... then I tell them to not use those speakers for HT use.
The biggest issue is subwoofers, most people getting into HT think they only need one and it can go anywhere in the room. Sure, that is what Bose states but in reality--you are adding a capability you have never messed with before so read up on proper subwoofer placement, use at least two of them and calibrate them correctly. Check what they are doing with meters to verify that the suck outs, ragged frequency response and all that inherent with subwoofers in traditional rooms have been tamed. If I hear them state "fast, quick or whatever" statements to subwoofers, I send them to data-bass.com to read how subwoofers work so they understand what is going on. At the minimum, you can use an SPL meter app on a phone and play a sweep on Youtube and it becomes obvious when they watch the meter jump around as it picks up the peaks and nulls from the sub.
Since most people do 2 channel "by ear", if the 5 to 11 channel HT system is setup properly with readings most people notice their 2 channel sounds better!
If you want 2 channel or 2.1 for music, look at Dolby's requirements for HT speakers and figure out what SPL level you require. If you have to have reference levels (0dB) be aware this takes very efficient speakers, plenty of power or both. 115dB SPL at your seated position down in the low 20Hz range takes quite a bit of air movement which can be calculated with online calculators. Just plug in the frequency, plug in your SPL and plug in the surface area of the sub (Sd on the spec page) It will tell you how far the sub has to move so keep adding subs until you get there. A great way to understand that for direct radiating subs, it is all dispacement or bore X stroke...in sub terms Sd X Xmax.
I have an old friend in his late 60's that didn't like the sub response for the system I set up for him in 2 channel. I rolled in a 35Hz high pass on the sub while he was in 2.1 mode and it made the sub "fast"
Uh...no... it filtered out sound below 35Hz which you are not used to hearing and for country/folk music/Beatles...you probably don't want to hear what is down there so get rid of it. Problem solved! He turns off the 35Hz high pass when watching movies or when listening to classical. That is a personal preference, if it sounds better to you... use it!
For people that have a lot of hearing damage from time or being a guitar player back in the day, the deep bass can be overpowering as they have no problem hearing low frequencies--the mids/highs are the issue so if you really want to know...get a hearing test and that will reveal your hearing issues. Adjust the EQ to match... your ears don't get better, they get worse so use the EQ and get speakers that don't distort in the treble if/when you boost the treble to make up for age related hearing loss.
Once you figure out the design and capabilities of the speakers you need for both HT and music--give them a listen with both music AND the spoken word. Your hearing is most critical with voices and the brain has many years of knowing if it is right or wrong. If the speaker sounds natural with a person talking (you can use just one speaker in mono to be natural) then try it with music. Music is much more complex for the brain to process and can hide flawed midrange problems. Using the spoken word in mono allows much easier pass/fail when it comes to speakers. Since HT is all about talking, get the speech correct as step 1.
Decent sources for the information you need to know can be found at audioholics (center channel/sub calibration) data-bass.com (subwoofer tests, what all those charts mean, myths of subwoofers, correct terminology for describing them and calibration) and dolby has information about how to set up different systems and the proper type of speaker, dispersion required, SPL requirements and calibration of the system.