Properly set up and calibrated, and that is asking alot; monopoles are superior if you are serious about multichannel reproduction. You asked about sides however. That is a complex question and there are various opinions here. Lexicon published a ground breaking white paper years ago suggesting side channel info was crutial in creating a believable soundspace with accurate surround sound atmospherics that is a good place to start experimenting. Their logic 7 mode was and still is a good dsp algorithm system . Tom Holman { not sure of spelling here} of THX fame is another outspoken engineer that has his theories. Widescreen Review and Gary Reber challenged the community years ago and postulated 5 identical , equidistant speakers properly calibrated with a radio shak meter { C- Slow } and most have slowly adopted his ideas. Including me. I went from processor to processor , speaker set up to set up and after what seems like a lifetime of intense study , I have found a multichannel system that is natural and effortless. I cant speak highly enough of the Meridian in this regard . I have abandonded the side channel all together as the cohesiveness of the soundfield is solid with 5 mains . You may find 7 channel more rewarding. Your question is about surrounds. If you are using only 2 speakers and must put them on the sides then conventional wisdom suggests dipoles. I do not find the effect natural for multichannel but on theatre , its ok. I prefer doing multichannel correctly and theatre will follow quite nicely. My thoughts are to start with less and progress as your observations about the room interaction and your particular taste grow and change with each move you make within the system. I would start with 5 . Place monopole { matched to mains as closely as possible } not directly behind you but at an angle about half way between behind and to the sides. I cant give a specific degree because in each room , things are different. USE AN SPL METER. Your friends will claim their ears are superior , I doubt it. Good luck and research past issues of Widescreen review such as the issue with Star Trek on the cover and the article penned by Peter Montcrief { spelling? } called "doing it right" is indespensible as a learning tool in this area even though it is a pre dolby digital article. Hope this long winded essay helps.