I do not have any actual experience with the 350… but I would still say MarCum all the way. I bought a MarCum LX-5 this year… and I couldn’t have been happier. Quality is the best. Customer Service is next to none!!!
If you do end up going with the MarCum… check out Jolly Ann Marine. They have extremely competitive prices and there is no shipping and no taxes outside of Iowa. They, too, have the best customer service. That is who I bought my LX-5 from and I have a Lowrance H2OC with MN Lakemaster chip on order with them right now.