I hesitated to add anything to this thread because of all of the cynical and suspicious replies I often see in response to my positive comments about Upton products. Then I decided that those should not prevent me from adding my opinion and saying what I believe. Yes, I live in Connecticut. Yes I am an Upton customer. No, I don't have any financial interest or "arrangement" with them. None.
So much for the preamble. Just this past Saturday, I had my bass at Upton for a winter "tweaking" (new sound post, check of all seams, fingerboard dressing, etc.) Because I was at the shop for quite a while, I got a chance to play a brand new Upton hybrid for longer than I had ever played one before. After my (fully carved) bass was finished on the bench, I asked Gary to play my bass and then handed him his hybrid. We went back and forth.
The Upton hybrid has a powerful deep tone and "feels" great to play. Having owned an earlier Upton hybrid a few years back (not the Hawkes) that I adored, I can say that the current Hawkes represents a marked improvement all around. To my critical but non-luthier eye, the workmanship is great. I simply cannot imagine, nor have I seen, a better bang for the bass buck.
Okay, so you're probably wondering about the head-to-head with my carved. Here's what I heard. The two basses were about even in terms of power in the low end. The Hawkes
may have had a touch more power in that regard perhaps as a result of its bigger body. The complexity of tone that one would expect of a carved top was quite apparent to me. It sounds nothing like a typical laminate bass. To my ear, my own bass transmitted the upper partials with more clarity. That may account for the Hawkes seeming to have more power in the low end-- it may have
relatively more power. My own has a "sweeter" sound that I like better but, then again, I
have to! Gee, it also costs a bit more.

Perhaps the most significant aspect of the comparison was how well the hybrid held up against my own and other carved basses in the shop. IMHO, buying one "sound unheard" represents minimal to no risk at all.
Yes, ideally, one should play the bass he/she is going to buy. Now, others are free to disagree, but I think this is much
more of an issue when buying a carved bass at a higher price point. Speaking of price-points, one is likely to wonder just how long the Upton Hybrid will sit where it is.