To address the increasing capacity demand due to adoption of data-intensive services and broadband devices, densification of mobile networks by small cell deployments has been considered as one key systematic solution for both legacy fourth generation (4G) mobile networks and future fifth generation (5G) network upgrades. The cost-efficiency and capacity gains due to small cell deployments can be further enhanced by optimizing the number and locations of the dense small cell deployments. With network densification by 4G small cells imminent while 5G small cell upgrades envisioned, an interesting network planning dilemma emerges on whether to optimize small cell deployments for 4G or 5G small cells. In this paper, we confront this dilemma by utilizing multiobjective optimization (MO) based planning approach for comparing and contrasting performance of small cell topologies optimized for 4G and 5G deployments. Propagation computation is performed using deterministic ray-tracing dominant path model over a building and terrain map of the deployment scenario. Results show that 5G optimized scenario provides considerable network capacity gains compared to 4G optimized 5G co-location scenario for different optimal small cell topologies with same number of small cells. For instance, for 31 small cells topologies, it presents 21.5% more capacity gain relative to 4G optimized case. Furthermore, 5G optimized case presents 38% and 5% more peak and cell-edge user throughput gains, respectively.