Looks like a great switch!
Note that if you want to use hardware offloading for L3 routing, the 98DX226S switch chip in this model doesn't support Fasttrack or NAT offloading.
That is strange. As long as it can route/switch packets without drops when it is fully loaded and with lots of rules.....
Switching is always at wire speed with most Mikrotik switches, as it's done directly in the switch chip. You can check this in their block diagram.
Routing depends on exactly how you configure your routing. If you look at the block diagram, you'll see that there's only a 1.3Gbps connection between the switch chip and the CPU, so that (plus the fact that it's an 800Mhz CPU) will be your bottleneck for anything CPU-bound. You can see that 1.3Gbps limit in the routing benchmarks in their test results on their site (
MikroTik)
Since the switch chip in this model doesn't support Fasttrack, more things will have to go via the CPU than on a chip with fasttrack support.
If it supported Fasttrack, you could hit much faster routing speeds. Fasttrack bypasses the software routing for established connections, so that it can happen entirely within the switch chip. When a connection is attempted, it'll first run through all the firewall rules. However, once the connection is established (i.e. it's allowed based on your firewall rules), all future traffic across that connection can bypass the firewall. The catch with fasttrack is that it only supports ~2250-4500 connections and ~2250-4000 NAT entries, after which only the connections with the most throughput will be fasttracked.