On fire lately.
The pump and severe muscle soreness (DOMS) aren't necessarily bad (except excessive DOMS is well, excessive), but they also aren't a surefire or only method of determining a good workout or effective stimulation. It's a tricky thing because people will start to train for pain as opposed to training to stimulate growth and performance.
Yeah the pump is shown to correlate towards increasing hypertrophy. People often forget that hypertrophy is a product of cell swelling, lactic acid accumulation and mechanical tension. Lifting heavy weights isn't necessarily going to make you bigger if you just have the mentality of moving that weight from point A to B without specification and intention of muscle usage.