The off- axis response is noticeably different, as several above have said. The more directly in front of your speaker you can be, the more accurately you will hear full response with your guitar. The change can be radical with as little as 15 to 20 degrees from dead center. Also lower frequencies need more space to propagate (develop), so further from you cabinet will give a more full-range sound. Another option if you're using a combo or a smallish speaker cabinet is to set it angled on a chair (less safe in traffic) or On-Stage Stands makes an angled speaker stand. I use one regularly, if I can't bring and stack my two Acme Low B-2 cabinets. They're available from GC and SA as well as online shops.
Paul, keep your eyes open for open stage / open mic nights at local music clubs. There aren't as many as there were a few years ago, but that's how I met the guys that formed Pickled BEATS, and several other good local players. Does Milwaukee have a local nightlife /entertainment magazine.? In Chicago we've got Illinois Entertainer and Suburban Nightlife. Also look for bulletin boards in local music store foyers. I used to do two jams every week at the end of the century...
Mike