I like to have a challenge in my encounters, especially for AVs/Heros that spawn at level 20 or higher. The added -1 thru +4 depends on how much health I want them to have. If my character needs a boost, I'll use whatever means to improve (Shivans/Signature Summons/Longbow Mech, etc., Warburg Nukes, temporary powers, inspirations, dual boxing support, kiting/pulling, accolade powers, etc). The only thing I haven't used are geometry breaks, because, aside from trying to solo Hamidon, it breaks the veil of fun for me. To each their own!
🙃