I know many huge guys who don't train to failure. In fact doing so too frequently can cause nervous system burn-out and slow/stop strength gains. The next time you go to your gym when it is crowded, look around to see which people are doing forced reps at the end of every set. You will notice that many of these guys have not made gains in years and are not really that strong. The best bencher at my gym never uses a spotter, even for a lift-off.
The key (at least for me) in growing is gradually increasing the weight and thus demand on the body. I've made much better muscle mass gains following various progresive powerlifting programs (which avoid training to failure) than traditional BBing programs (espec HIT, LOL).
You could also do tons of moderate weight sets without going to failure. This is the way Lee Priest trains.
Another advantage to not having the spotter is that you have no distractions (just wear a discman and lift, instead of talking for 10 minuites between sets). Kevin Levrone (who trains very heavy when he does lift) says that the key change he made in preparing for the last Olympia was ditching his training partner. This allowed him to really focus during his workouts.