i definetly prefer to train with a partner, but i train alone most of the time. hard to find people who take their training seriously enough around here.
I've trained with the same dude for 2 years now...most the time I enjoy it for the simple fact you push each other and always have that spot when you need it. But there are those days were we don't agree on certain exercises or the pace etc. So ya once in awhile I enjoy to train solo but for the most part its a combo
I like training with other people, but I train solo.
I've found that their are many advantages but a lot of disadvantages. Scheduling is always a big issue. How motivated the other person is and whether they are at your level is also a big factor. Whether it becomes a talk fest or a two man lift fest is another issue. Just because you train with someone doesn't mean the workout should take longer, nor that you should ever need a spot (why is it that as soon as you ask for a liftoff on bench everyone wants to grab the bar and say it is all you?? I wouldn't put the weight on the bar if I couldn't lift the bloody thing).
Plus training partners often seem to be in two categories: Frat or HC. The latter are rare and usually pretty serious lifters. The frat or others are just as much about posing and chatting as anything and usually hog equipment.