Whilst trawling the forums for information on the Artist Balladeer 1621 I found that the practical information is kind of sparse.

According to my findings the Artist Balladeer was the economy model back in the day. Technical data (Ovation website):

Body Type: Shallow Bowl
Top: Sitka Spruce AA
Bracing: Ovation VT-8
Scale Length: 25 1/4"
Fretboard: Ebony
Fret Inlay: 8 Pearl
Bridge: Walnut
Pickup: Piezoelectric
Nutwidth: 1 11/16"
Machines: Deluxe Chrome

Today I had the opportunity to play exactly a 1621 and my observations and impressions are as follows:

The tested 1621 was from 1975. I didn't buy it because of a crack in the soundboard, not mentioned by the seller, running from the saddle to the bottom. Apart from that is was in a reasonable condition for a 40 year old guitar.

The neck is with a conventional truss rod, i.e. pre Kaman bar. The profile is slightly slimmer than a K-bar neck but not a whole world of difference. It is noticeable lighter in weight than a K-bar neck. Playability and handling is very good.

The electronics includes only a volume control.

The Artist bowl is shallow - not supershallow. Effectively between the present day supershallow and medium. No cutaway. Nice and comfortable and very light construction.

Soundwise I was impressed by the acoustic sound although the strings were a bit dull. The sound was open and well articulated especially well suited for fingerpicking or for soloing, A little less impressive when strumming. The volume and overall sound characteristics were as one would expect of a thin bodied guitar in the better end of the spectrum. Plugged in sound was fine but suffers a bit in the low end. If used alone an external tone control (pedal or on the amplifier) to enhance the bottom a bit will serve well. This is probably not required when used with a band. The descriptions found on the net suit it well with the sonic focus being clear mids and highs with the bass being a bit leaner.

During my initial research I was kind of discouraged by the bad reputation of the VT-8 bracing. However in my subjective experience, to my personal ears and fingers this guitar is strongly underrated, and I still struggle a bit with myself if I should learn to live with that crack in the top.