Bifen I/T is one of our most popular products for mosquito control. Bifen XTS is basically the same product, just in a higher concentration, and oil-based instead of water-based. For mosquito control you do not need the higher concentration, it is not necessary. The most important thing to remember when treating for mosquitoes is that they hang out on the underside of leaves and shrubs. You should treat all shrubs, bushes and trees, remembering to not only treat the main bush or shrub but also the underside of the leaves. Mosquitoes lay their eggs in standing water, so if there are any areas of standing water where you are treating, those should be treated as well with BTI Mosquito Dunks or Altosid Pro-G Mosquito Larvicide.
You may also want to look over our Mosquito Control Article if you have a moment.
Either sprayer or mister application would be effective with either product as long as the application is thorough. Oil-based products such as Bifen XTS can stain some surfaces. This is not usually a concern in most areas outside, but you should use caution when treating around the siding of a home. Most oil-based products such as Bifen XTS do have a "chemical" odor but it is not especially strong.
Both Bifen I/T and Bifen XTS can cause moderate skin irritation. Be sure to use adequate skin protection as outlined on the product label, such as wearing gloves and long pants/sleeves to avoid this.