I bought one for Wahoo Trolling, Chris got me one for a good price during Sams Stop n Shop spring sale last year. I've only had it deployed a couple times, and we haven't landed a fish with it yet, but so far I like it. It has done well pulling a Large Cowbell lure at about 15kt. Lightweight graphite construction, heavy duty drag washers, fairly comfortable original power handle...
...and the cost is cheaper than investing in a big International reel!
Hopefully you'll get some more input from some who have fought some fish on them!
When the squall series was initially introduced, I was skeptical due to the poor performance of its predecessors (GLD and Formula series) and as a result, acquired a few models for evaluation. Mark and I took turns taking our demo set out and after a good season of use against Swords, Tuna and a couple billfish, we determined they were as capable as a TLD and possibly an even better value.
I've fished a set of TLD 50s for a while now and are extremely happy with them, but the added line capacity of the Squall 50VSW in conjunction with a great drag and simple, effective shifting system prove its something to be strongly considered.
I know it is a totally different reel, but I have a pair of SQL50ld's that I got at a good price and use them for chunking tuna. We have landed a lot of 40-100 pound yft on them and they have performed great, a little undersized, but still have no complaints.