Where I grew up, we had multiple mature lilac bushes that I just adored the smell of, so when I bought my first home, and a few years into it the ancient stump sticking out of the ground suddenly began sprouting new branches and identified itself as the most glorious lilac I'd ever seen. When we moved to the farm, I bought tiny starts and they struggled to survive, so upon downsizing back to the city, I made the conscious decision to do what I call "Buying Time" - i.e., spending money on more mature plants to give them an advantage on survival - AND allow me to see them blooming much, much more quickly. And boy oh boy has it proven to be a smart move!
This one, the Ludwig Spaeth - a late-blooming French Hybrid Lilac first introduced in 1883 - has both filled in profusely and nearly doubled in height in the year since I planted it, now reaching the top of the fence, with an expected 4' or more of height to help it become part of the privacy hedge we've been craving [after our uphill neighbor's landlord clearcut their lot last year, giving us full view of the neighbor's abandoned cars due to the slope of our street (oy!)]. I can't emphasize enough at how worth it it's been to invest in larger plants - buy once, cry once, as someone once said...
"I cannot understand why my arm is not a lilac tree." ~ Leonard Cohen