Agreed, most aluminum frames you will find have fugly HUGE welds. That said, I feel that there are some mad glorious aluminum frames out there, ie. pista concepts etc. The reason aluminum tends to feel stiffer is because it needs to be thicker and/or the tubes larger to achieve similar strength to steel. The weight difference makes these thicker tubes about the same weight or lighter, but you lose some of the flexibility you find in thinner, smaller tubes. Replace the fork with something carbon or steel and your ride should be fine.